Python Code Snippets

05014

Arrays

Lists 

<span># Creating a list </span><span>my_list</span> <span>=</span> <span>[]</span>
<span>my_list</span> <span>=</span> <span>[</span><span>0</span><span>,</span> <span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>,</span> <span>4</span><span>,</span> <span>5</span><span>,</span> <span>6</span><span>,</span> <span>7</span><span>,</span> <span>8</span><span>,</span> <span>9</span><span>]</span>
<span># List of different data types </span><span>mixed_list</span> <span>=</span> <span>[</span><span>1</span><span>,</span> <span>"</span><span>hello</span><span>"</span><span>,</span> <span>3.14</span><span>,</span> <span>True</span><span>]</span>
<span># Accessing elements </span><span>print</span><span>(</span><span>my_list</span><span>[</span><span>0</span><span>])</span>  <span># Output: 1 </span><span>print</span><span>(</span><span>my_list</span><span>[</span><span>-</span><span>1</span><span>])</span> <span># Output: 5 </span>
<span># Append to the end </span><span>my_list</span><span>.</span><span>append</span><span>(</span><span>6</span><span>)</span>
<span># Insert at a specific position </span><span>my_list</span><span>.</span><span>insert</span><span>(</span><span>2</span><span>,</span> <span>10</span><span>)</span>
<span># Find an element in an array </span><span>index</span><span>=</span><span>my_list</span><span>.</span><span>find</span><span>(</span><span>element</span><span>)</span>
<span># Remove by value </span><span>my_list</span><span>.</span><span>remove</span><span>(</span><span>10</span><span>)</span>
<span># Remove by index </span><span>removed_element</span> <span>=</span> <span>my_list</span><span>.</span><span>pop</span><span>(</span><span>2</span><span>)</span>
<span># Length of the list </span><span>print</span><span>(</span><span>len</span><span>(</span><span>my_list</span><span>))</span>
<span># Slicing [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] # sequence[start:stop:step] </span>
<span>print</span><span>(</span><span>my_list</span><span>[</span><span>1</span><span>:</span><span>4</span><span>])</span>  <span># Output: [1, 2, 3] </span><span>print</span><span>(</span><span>my_list</span><span>[</span><span>5</span><span>:])</span>  <span># Output: [5, 6, 7, 8, 9] </span><span>print</span><span>(</span><span>my_list</span><span>[:</span><span>5</span><span>])</span>  <span># Output: [0, 1, 2, 3, 4] </span><span>print</span><span>(</span><span>my_list</span><span>[::</span><span>2</span><span>])</span>  <span># Output: [0, 2, 4, 6, 8] </span><span>print</span><span>(</span><span>my_list</span><span>[</span><span>-</span><span>4</span><span>:])</span>  <span># Output: [6, 7, 8, 9] </span><span>print</span><span>(</span><span>my_list</span><span>[:</span><span>-</span><span>4</span><span>])</span>  <span># Output: [0, 1, 2, 3, 4, 5] </span><span>print</span><span>(</span><span>my_list</span><span>[::</span><span>-</span><span>1</span><span>])</span>  <span># Output: [9, 8, 7, 6, 5, 4, 3, 2, 1, 0] </span><span>print</span><span>(</span><span>my_list</span><span>[</span><span>8</span><span>:</span><span>2</span><span>:</span><span>-</span><span>2</span><span>])</span>  <span># Output: [8, 6, 4] </span><span>print</span><span>(</span><span>my_list</span><span>[</span><span>1</span><span>:</span><span>8</span><span>:</span><span>2</span><span>])</span>  <span># Output: [1, 3, 5, 7] </span><span>print</span><span>(</span><span>my_list</span><span>[</span><span>-</span><span>2</span><span>:</span><span>-</span><span>7</span><span>:</span><span>-</span><span>1</span><span>])</span>  <span># Output: [8, 7, 6, 5, 4] </span>
<span># Reversing a list </span><span>my_list</span><span>.</span><span>reverse</span><span>()</span>
<span># Sorting a list </span><span>my_list</span><span>.</span><span>sort</span><span>()</span>
<span># Creating a list </span><span>my_list</span> <span>=</span> <span>[]</span>
<span>my_list</span> <span>=</span> <span>[</span><span>0</span><span>,</span> <span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>,</span> <span>4</span><span>,</span> <span>5</span><span>,</span> <span>6</span><span>,</span> <span>7</span><span>,</span> <span>8</span><span>,</span> <span>9</span><span>]</span>

<span># List of different data types </span><span>mixed_list</span> <span>=</span> <span>[</span><span>1</span><span>,</span> <span>"</span><span>hello</span><span>"</span><span>,</span> <span>3.14</span><span>,</span> <span>True</span><span>]</span>

<span># Accessing elements </span><span>print</span><span>(</span><span>my_list</span><span>[</span><span>0</span><span>])</span>  <span># Output: 1 </span><span>print</span><span>(</span><span>my_list</span><span>[</span><span>-</span><span>1</span><span>])</span> <span># Output: 5 </span>
<span># Append to the end </span><span>my_list</span><span>.</span><span>append</span><span>(</span><span>6</span><span>)</span>

<span># Insert at a specific position </span><span>my_list</span><span>.</span><span>insert</span><span>(</span><span>2</span><span>,</span> <span>10</span><span>)</span>

<span># Find an element in an array </span><span>index</span><span>=</span><span>my_list</span><span>.</span><span>find</span><span>(</span><span>element</span><span>)</span>

<span># Remove by value </span><span>my_list</span><span>.</span><span>remove</span><span>(</span><span>10</span><span>)</span>

<span># Remove by index </span><span>removed_element</span> <span>=</span> <span>my_list</span><span>.</span><span>pop</span><span>(</span><span>2</span><span>)</span>

<span># Length of the list </span><span>print</span><span>(</span><span>len</span><span>(</span><span>my_list</span><span>))</span>

<span># Slicing [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] # sequence[start:stop:step] </span>
<span>print</span><span>(</span><span>my_list</span><span>[</span><span>1</span><span>:</span><span>4</span><span>])</span>  <span># Output: [1, 2, 3] </span><span>print</span><span>(</span><span>my_list</span><span>[</span><span>5</span><span>:])</span>  <span># Output: [5, 6, 7, 8, 9] </span><span>print</span><span>(</span><span>my_list</span><span>[:</span><span>5</span><span>])</span>  <span># Output: [0, 1, 2, 3, 4] </span><span>print</span><span>(</span><span>my_list</span><span>[::</span><span>2</span><span>])</span>  <span># Output: [0, 2, 4, 6, 8] </span><span>print</span><span>(</span><span>my_list</span><span>[</span><span>-</span><span>4</span><span>:])</span>  <span># Output: [6, 7, 8, 9] </span><span>print</span><span>(</span><span>my_list</span><span>[:</span><span>-</span><span>4</span><span>])</span>  <span># Output: [0, 1, 2, 3, 4, 5] </span><span>print</span><span>(</span><span>my_list</span><span>[::</span><span>-</span><span>1</span><span>])</span>  <span># Output: [9, 8, 7, 6, 5, 4, 3, 2, 1, 0] </span><span>print</span><span>(</span><span>my_list</span><span>[</span><span>8</span><span>:</span><span>2</span><span>:</span><span>-</span><span>2</span><span>])</span>  <span># Output: [8, 6, 4] </span><span>print</span><span>(</span><span>my_list</span><span>[</span><span>1</span><span>:</span><span>8</span><span>:</span><span>2</span><span>])</span>  <span># Output: [1, 3, 5, 7] </span><span>print</span><span>(</span><span>my_list</span><span>[</span><span>-</span><span>2</span><span>:</span><span>-</span><span>7</span><span>:</span><span>-</span><span>1</span><span>])</span>  <span># Output: [8, 7, 6, 5, 4] </span>
<span># Reversing a list </span><span>my_list</span><span>.</span><span>reverse</span><span>()</span>

<span># Sorting a list </span><span>my_list</span><span>.</span><span>sort</span><span>()</span>
# Creating a list my_list = []
my_list = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

# List of different data types mixed_list = [1, "hello", 3.14, True]

# Accessing elements print(my_list[0])  # Output: 1 print(my_list[-1]) # Output: 5 
# Append to the end my_list.append(6)

# Insert at a specific position my_list.insert(2, 10)

# Find an element in an array index=my_list.find(element)

# Remove by value my_list.remove(10)

# Remove by index removed_element = my_list.pop(2)

# Length of the list print(len(my_list))

# Slicing [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] # sequence[start:stop:step] 
print(my_list[1:4])  # Output: [1, 2, 3] print(my_list[5:])  # Output: [5, 6, 7, 8, 9] print(my_list[:5])  # Output: [0, 1, 2, 3, 4] print(my_list[::2])  # Output: [0, 2, 4, 6, 8] print(my_list[-4:])  # Output: [6, 7, 8, 9] print(my_list[:-4])  # Output: [0, 1, 2, 3, 4, 5] print(my_list[::-1])  # Output: [9, 8, 7, 6, 5, 4, 3, 2, 1, 0] print(my_list[8:2:-2])  # Output: [8, 6, 4] print(my_list[1:8:2])  # Output: [1, 3, 5, 7] print(my_list[-2:-7:-1])  # Output: [8, 7, 6, 5, 4] 
# Reversing a list my_list.reverse()

# Sorting a list my_list.sort()

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Permutation & Combination 

<span>import</span> <span>itertools</span>
<span># Example list </span><span>data</span> <span>=</span> <span>[</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>]</span>
<span># Generating permutations of the entire list </span><span>perms</span> <span>=</span> <span>list</span><span>(</span><span>itertools</span><span>.</span><span>permutations</span><span>(</span><span>data</span><span>))</span>
<span>print</span><span>(</span><span>perms</span><span>)</span>
<span># Output: [(1, 2, 3), (1, 3, 2), (2, 1, 3), (2, 3, 1), (3, 1, 2), (3, 2, 1)] </span>
<span># Generating permutations of length 2 </span><span>perms_length_2</span> <span>=</span> <span>list</span><span>(</span><span>itertools</span><span>.</span><span>permutations</span><span>(</span><span>data</span><span>,</span> <span>2</span><span>))</span>
<span>print</span><span>(</span><span>perms_length_2</span><span>)</span>
<span># Output: [(1, 2), (1, 3), (2, 1), (2, 3), (3, 1), (3, 2)] </span>
<span>combinations</span><span>(</span><span>iterable</span><span>,</span> <span>r</span><span>)</span> <span>#order does not matter </span>
<span>import</span> <span>itertools</span>

<span># Example list </span><span>data</span> <span>=</span> <span>[</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>]</span>

<span># Generating permutations of the entire list </span><span>perms</span> <span>=</span> <span>list</span><span>(</span><span>itertools</span><span>.</span><span>permutations</span><span>(</span><span>data</span><span>))</span>
<span>print</span><span>(</span><span>perms</span><span>)</span>
<span># Output: [(1, 2, 3), (1, 3, 2), (2, 1, 3), (2, 3, 1), (3, 1, 2), (3, 2, 1)] </span>
<span># Generating permutations of length 2 </span><span>perms_length_2</span> <span>=</span> <span>list</span><span>(</span><span>itertools</span><span>.</span><span>permutations</span><span>(</span><span>data</span><span>,</span> <span>2</span><span>))</span>
<span>print</span><span>(</span><span>perms_length_2</span><span>)</span>
<span># Output: [(1, 2), (1, 3), (2, 1), (2, 3), (3, 1), (3, 2)] </span>
<span>combinations</span><span>(</span><span>iterable</span><span>,</span> <span>r</span><span>)</span> <span>#order does not matter </span>
import itertools

# Example list data = [1, 2, 3]

# Generating permutations of the entire list perms = list(itertools.permutations(data))
print(perms)
# Output: [(1, 2, 3), (1, 3, 2), (2, 1, 3), (2, 3, 1), (3, 1, 2), (3, 2, 1)] 
# Generating permutations of length 2 perms_length_2 = list(itertools.permutations(data, 2))
print(perms_length_2)
# Output: [(1, 2), (1, 3), (2, 1), (2, 3), (3, 1), (3, 2)] 
combinations(iterable, r) #order does not matter

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Generating Permutations Manually
You can also generate permutations manually using recursion. Here’s a simple implementation: 

<span>def</span> <span>permute</span><span>(</span><span>arr</span><span>):</span>
    <span>result</span> <span>=</span> <span>[]</span>
    <span># Base case: if the list is empty, return an empty list </span>    <span>if</span> <span>len</span><span>(</span><span>arr</span><span>)</span> <span>==</span> <span>0</span><span>:</span>
        <span>return</span> <span>[[]]</span>
    <span># Recursive case </span>    <span>for</span> <span>i</span> <span>in</span> <span>range</span><span>(</span><span>len</span><span>(</span><span>arr</span><span>)):</span>
        <span>elem</span> <span>=</span> <span>arr</span><span>[</span><span>i</span><span>]</span>
        <span>rest</span> <span>=</span> <span>arr</span><span>[:</span><span>i</span><span>]</span> <span>+</span> <span>arr</span><span>[</span><span>i</span><span>+</span><span>1</span><span>:]</span>
        <span>for</span> <span>p</span> <span>in</span> <span>permute</span><span>(</span><span>rest</span><span>):</span>
            <span>result</span><span>.</span><span>append</span><span>([</span><span>elem</span><span>]</span> <span>+</span> <span>p</span><span>)</span>
    <span>return</span> <span>result</span>
<span>def</span> <span>permute</span><span>(</span><span>arr</span><span>):</span>
    <span>result</span> <span>=</span> <span>[]</span>

    <span># Base case: if the list is empty, return an empty list </span>    <span>if</span> <span>len</span><span>(</span><span>arr</span><span>)</span> <span>==</span> <span>0</span><span>:</span>
        <span>return</span> <span>[[]]</span>

    <span># Recursive case </span>    <span>for</span> <span>i</span> <span>in</span> <span>range</span><span>(</span><span>len</span><span>(</span><span>arr</span><span>)):</span>
        <span>elem</span> <span>=</span> <span>arr</span><span>[</span><span>i</span><span>]</span>
        <span>rest</span> <span>=</span> <span>arr</span><span>[:</span><span>i</span><span>]</span> <span>+</span> <span>arr</span><span>[</span><span>i</span><span>+</span><span>1</span><span>:]</span>
        <span>for</span> <span>p</span> <span>in</span> <span>permute</span><span>(</span><span>rest</span><span>):</span>
            <span>result</span><span>.</span><span>append</span><span>([</span><span>elem</span><span>]</span> <span>+</span> <span>p</span><span>)</span>

    <span>return</span> <span>result</span>
def permute(arr):
    result = []

    # Base case: if the list is empty, return an empty list     if len(arr) == 0:
        return [[]]

    # Recursive case     for i in range(len(arr)):
        elem = arr[i]
        rest = arr[:i] + arr[i+1:]
        for p in permute(rest):
            result.append([elem] + p)

    return result

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Stack

(list can be used as stack) 

<span>st</span><span>=</span><span>[]</span>
<span>st</span><span>.</span><span>append</span><span>()</span>
<span>st</span><span>.</span><span>pop</span><span>()</span>
<span>top_element</span> <span>=</span> <span>stack</span><span>[</span><span>-</span><span>1</span><span>]</span>
<span>st</span><span>=</span><span>[]</span>
<span>st</span><span>.</span><span>append</span><span>()</span>
<span>st</span><span>.</span><span>pop</span><span>()</span>
<span>top_element</span> <span>=</span> <span>stack</span><span>[</span><span>-</span><span>1</span><span>]</span>
st=[]
st.append()
st.pop()
top_element = stack[-1]

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Tips

1) Strip:
It is used to remove leading and trailing whitespace (or other specified characters) from a string 

<span>#EX. (1,2) to 1,2 </span><span>s</span><span>.</span><span>strip</span><span>(</span><span>'</span><span>()</span><span>'</span><span>)</span>
<span>#EX. (1,2) to 1,2 </span><span>s</span><span>.</span><span>strip</span><span>(</span><span>'</span><span>()</span><span>'</span><span>)</span>
#EX. (1,2) to 1,2 s.strip('()')

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2) Don’t use normal dictionary 

<span>from</span> <span>collections</span> <span>import</span> <span>defaultdict</span>
<span>dictionary</span><span>=</span><span>defaultdict</span><span>(</span><span>int</span><span>)</span>
<span>from</span> <span>collections</span> <span>import</span> <span>defaultdict</span>
<span>dictionary</span><span>=</span><span>defaultdict</span><span>(</span><span>int</span><span>)</span>
from collections import defaultdict
dictionary=defaultdict(int)

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3) Important checking and convertion 

<span>s</span><span>.</span><span>isdigit</span><span>()</span>
<span>s</span><span>.</span><span>isalpha</span><span>()</span>
<span>s</span><span>.</span><span>isalnum</span><span>()</span>
<span>s</span><span>.</span><span>islower</span><span>()</span>
<span>s</span><span>.</span><span>isupper</span><span>()</span>
<span>s</span><span>.</span><span>lower</span><span>()</span>
<span>s</span><span>.</span><span>upper</span><span>()</span>
<span>s</span><span>.</span><span>isdigit</span><span>()</span>
<span>s</span><span>.</span><span>isalpha</span><span>()</span>
<span>s</span><span>.</span><span>isalnum</span><span>()</span>
<span>s</span><span>.</span><span>islower</span><span>()</span>
<span>s</span><span>.</span><span>isupper</span><span>()</span>
<span>s</span><span>.</span><span>lower</span><span>()</span>
<span>s</span><span>.</span><span>upper</span><span>()</span>
s.isdigit()
s.isalpha()
s.isalnum()
s.islower()
s.isupper()
s.lower()
s.upper()

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4) Non-Trivial 

<span>round</span><span>(</span><span>number</span><span>,</span> <span>decimal_digits</span><span>)</span>
<span>ord</span><span>(</span><span>each</span><span>)</span><span>-</span><span>ord</span><span>(</span><span>'</span><span>a</span><span>'</span><span>)</span><span>+</span><span>1</span> <span># value of an alphabet #/ (Floating-Point Division) #// (Floor Division) </span><span>maxim</span> <span>=</span> <span>float</span><span>(</span><span>'</span><span>-inf</span><span>'</span><span>)</span>
<span>minim</span> <span>=</span> <span>float</span><span>(</span><span>'</span><span>inf</span><span>'</span><span>)</span>
<span>unique_lengths</span><span>.</span><span>sort</span><span>(</span><span>reverse</span><span>=</span><span>True</span><span>)</span>
<span>s</span><span>.</span><span>count</span><span>(</span><span>'</span><span>x</span><span>'</span><span>)</span>
<span>list1</span> <span>=</span> <span>[</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>]</span>
<span>iterable</span> <span>=</span> <span>[</span><span>4</span><span>,</span> <span>5</span><span>,</span> <span>6</span><span>]</span>
<span>list1</span><span>.</span><span>extend</span><span>(</span><span>iterable</span><span>)</span>
<span>position</span><span>.</span><span>replace</span><span>(</span><span>'</span><span>(</span><span>'</span><span>,</span> <span>''</span><span>).</span><span>replace</span><span>(</span><span>'</span><span>)</span><span>'</span><span>,</span> <span>''</span><span>)</span>
<span>expression</span> <span>=</span> <span>"</span><span>2 + 3 * 4</span><span>"</span>
<span>result</span> <span>=</span> <span>eval</span><span>(</span><span>expression</span><span>)</span>
<span>print</span><span>(</span><span>result</span><span>)</span> 
<span>#Determinant </span><span>import</span> <span>numpy</span> <span>as</span> 
<span>arr</span><span>=</span><span>[[</span><span>1</span><span>,</span><span>2</span><span>,</span><span>3</span><span>],[</span><span>3</span><span>,</span><span>4</span><span>,</span><span>5</span><span>],[</span><span>5</span><span>,</span><span>6</span><span>,</span><span>7</span><span>]]</span>
<span>print</span><span>(</span><span>np</span><span>.</span><span>linalg</span><span>.</span><span>det</span><span>(</span><span>np</span><span>.</span><span>array</span><span>(</span><span>arr</span><span>)))</span>
<span>round</span><span>(</span><span>number</span><span>,</span> <span>decimal_digits</span><span>)</span>
<span>ord</span><span>(</span><span>each</span><span>)</span><span>-</span><span>ord</span><span>(</span><span>'</span><span>a</span><span>'</span><span>)</span><span>+</span><span>1</span> <span># value of an alphabet #/ (Floating-Point Division) #// (Floor Division) </span><span>maxim</span> <span>=</span> <span>float</span><span>(</span><span>'</span><span>-inf</span><span>'</span><span>)</span>
<span>minim</span> <span>=</span> <span>float</span><span>(</span><span>'</span><span>inf</span><span>'</span><span>)</span>
<span>unique_lengths</span><span>.</span><span>sort</span><span>(</span><span>reverse</span><span>=</span><span>True</span><span>)</span>
<span>s</span><span>.</span><span>count</span><span>(</span><span>'</span><span>x</span><span>'</span><span>)</span>

<span>list1</span> <span>=</span> <span>[</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>]</span>
<span>iterable</span> <span>=</span> <span>[</span><span>4</span><span>,</span> <span>5</span><span>,</span> <span>6</span><span>]</span>
<span>list1</span><span>.</span><span>extend</span><span>(</span><span>iterable</span><span>)</span>

<span>position</span><span>.</span><span>replace</span><span>(</span><span>'</span><span>(</span><span>'</span><span>,</span> <span>''</span><span>).</span><span>replace</span><span>(</span><span>'</span><span>)</span><span>'</span><span>,</span> <span>''</span><span>)</span>

<span>expression</span> <span>=</span> <span>"</span><span>2 + 3 * 4</span><span>"</span>
<span>result</span> <span>=</span> <span>eval</span><span>(</span><span>expression</span><span>)</span>
<span>print</span><span>(</span><span>result</span><span>)</span> 

<span>#Determinant </span><span>import</span> <span>numpy</span> <span>as</span> 
<span>arr</span><span>=</span><span>[[</span><span>1</span><span>,</span><span>2</span><span>,</span><span>3</span><span>],[</span><span>3</span><span>,</span><span>4</span><span>,</span><span>5</span><span>],[</span><span>5</span><span>,</span><span>6</span><span>,</span><span>7</span><span>]]</span>
<span>print</span><span>(</span><span>np</span><span>.</span><span>linalg</span><span>.</span><span>det</span><span>(</span><span>np</span><span>.</span><span>array</span><span>(</span><span>arr</span><span>)))</span>
round(number, decimal_digits)
ord(each)-ord('a')+1 # value of an alphabet #/ (Floating-Point Division) #// (Floor Division) maxim = float('-inf')
minim = float('inf')
unique_lengths.sort(reverse=True)
s.count('x')

list1 = [1, 2, 3]
iterable = [4, 5, 6]
list1.extend(iterable)

position.replace('(', '').replace(')', '')

expression = "2 + 3 * 4"
result = eval(expression)
print(result) 

#Determinant import numpy as 
arr=[[1,2,3],[3,4,5],[5,6,7]]
print(np.linalg.det(np.array(arr)))

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Sorted 

<span>my_list</span> <span>=</span> <span>[</span><span>3</span><span>,</span> <span>1</span><span>,</span> <span>4</span><span>,</span> <span>1</span><span>,</span> <span>5</span><span>]</span>
<span>sorted_list</span> <span>=</span> <span>sorted</span><span>(</span><span>my_list</span><span>)</span>
<span>my_tuple</span> <span>=</span> <span>(</span><span>3</span><span>,</span> <span>1</span><span>,</span> <span>4</span><span>,</span> <span>1</span><span>,</span> <span>5</span><span>)</span>
<span>sorted_list</span> <span>=</span> <span>sorted</span><span>(</span><span>my_tuple</span><span>)</span>
<span>my_dict</span> <span>=</span> <span>{</span><span>'</span><span>apple</span><span>'</span><span>:</span> <span>3</span><span>,</span> <span>'</span><span>banana</span><span>'</span><span>:</span> <span>1</span><span>,</span> <span>'</span><span>cherry</span><span>'</span><span>:</span> <span>2</span><span>}</span>
<span>sorted_keys</span> <span>=</span> <span>sorted</span><span>(</span><span>my_dict</span><span>)</span>
<span>my_list</span> <span>=</span> <span>[</span><span>3</span><span>,</span> <span>1</span><span>,</span> <span>4</span><span>,</span> <span>1</span><span>,</span> <span>5</span><span>]</span>
<span>sorted_list</span> <span>=</span> <span>sorted</span><span>(</span><span>my_list</span><span>,</span> <span>reverse</span><span>=</span><span>True</span><span>)</span>
<span>my_list</span> <span>=</span> <span>[</span><span>3</span><span>,</span> <span>1</span><span>,</span> <span>4</span><span>,</span> <span>1</span><span>,</span> <span>5</span><span>]</span>
<span>sorted_list</span> <span>=</span> <span>sorted</span><span>(</span><span>my_list</span><span>)</span>

<span>my_tuple</span> <span>=</span> <span>(</span><span>3</span><span>,</span> <span>1</span><span>,</span> <span>4</span><span>,</span> <span>1</span><span>,</span> <span>5</span><span>)</span>
<span>sorted_list</span> <span>=</span> <span>sorted</span><span>(</span><span>my_tuple</span><span>)</span>

<span>my_dict</span> <span>=</span> <span>{</span><span>'</span><span>apple</span><span>'</span><span>:</span> <span>3</span><span>,</span> <span>'</span><span>banana</span><span>'</span><span>:</span> <span>1</span><span>,</span> <span>'</span><span>cherry</span><span>'</span><span>:</span> <span>2</span><span>}</span>
<span>sorted_keys</span> <span>=</span> <span>sorted</span><span>(</span><span>my_dict</span><span>)</span>

<span>my_list</span> <span>=</span> <span>[</span><span>3</span><span>,</span> <span>1</span><span>,</span> <span>4</span><span>,</span> <span>1</span><span>,</span> <span>5</span><span>]</span>
<span>sorted_list</span> <span>=</span> <span>sorted</span><span>(</span><span>my_list</span><span>,</span> <span>reverse</span><span>=</span><span>True</span><span>)</span>
my_list = [3, 1, 4, 1, 5]
sorted_list = sorted(my_list)

my_tuple = (3, 1, 4, 1, 5)
sorted_list = sorted(my_tuple)

my_dict = {'apple': 3, 'banana': 1, 'cherry': 2}
sorted_keys = sorted(my_dict)

my_list = [3, 1, 4, 1, 5]
sorted_list = sorted(my_list, reverse=True)

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Enumerate 

<span>my_list</span> <span>=</span> <span>[</span><span>'</span><span>a</span><span>'</span><span>,</span> <span>'</span><span>b</span><span>'</span><span>,</span> <span>'</span><span>c</span><span>'</span><span>]</span>
<span>for</span> <span>index</span><span>,</span> <span>value</span> <span>in</span> <span>enumerate</span><span>(</span><span>my_list</span><span>):</span>
    <span>print</span><span>(</span><span>index</span><span>,</span> <span>value</span><span>)</span>
<span>my_list</span> <span>=</span> <span>[</span><span>'</span><span>a</span><span>'</span><span>,</span> <span>'</span><span>b</span><span>'</span><span>,</span> <span>'</span><span>c</span><span>'</span><span>]</span>
<span>for</span> <span>index</span><span>,</span> <span>value</span> <span>in</span> <span>enumerate</span><span>(</span><span>my_list</span><span>):</span>
    <span>print</span><span>(</span><span>index</span><span>,</span> <span>value</span><span>)</span>
my_list = ['a', 'b', 'c']
for index, value in enumerate(my_list):
    print(index, value)

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Pass by Object Reference

Immutable Types (like integers, strings, tuples): 

<span>def</span> <span>modify_immutable</span><span>(</span><span>x</span><span>):</span>
    <span>x</span> <span>=</span> <span>10</span>  <span># Rebinding the local variable to a new object </span>    <span>print</span><span>(</span><span>"</span><span>Inside function:</span><span>"</span><span>,</span> <span>x</span><span>)</span>
<span>a</span> <span>=</span> <span>5</span>
<span>modify_immutable</span><span>(</span><span>a</span><span>)</span> <span>#prints 10 </span><span>print</span><span>(</span><span>"</span><span>Outside function:</span><span>"</span><span>,</span> <span>a</span><span>)</span> <span>#prints 5 </span>
<span>def</span> <span>modify_immutable</span><span>(</span><span>x</span><span>):</span>
    <span>x</span> <span>=</span> <span>10</span>  <span># Rebinding the local variable to a new object </span>    <span>print</span><span>(</span><span>"</span><span>Inside function:</span><span>"</span><span>,</span> <span>x</span><span>)</span>

<span>a</span> <span>=</span> <span>5</span>
<span>modify_immutable</span><span>(</span><span>a</span><span>)</span> <span>#prints 10 </span><span>print</span><span>(</span><span>"</span><span>Outside function:</span><span>"</span><span>,</span> <span>a</span><span>)</span> <span>#prints 5 </span>
def modify_immutable(x):
    x = 10  # Rebinding the local variable to a new object     print("Inside function:", x)

a = 5
modify_immutable(a) #prints 10 print("Outside function:", a) #prints 5

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Mutable Types (like lists, dictionaries, sets): 

<span>def</span> <span>modify_mutable</span><span>(</span><span>lst</span><span>):</span>
    <span>lst</span><span>.</span><span>append</span><span>(</span><span>4</span><span>)</span>  <span># Modifying the original list object </span>    <span>print</span><span>(</span><span>"</span><span>Inside function:</span><span>"</span><span>,</span> <span>lst</span><span>)</span>
<span>my_list</span> <span>=</span> <span>[</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>]</span>
<span>modify_mutable</span><span>(</span><span>my_list</span><span>)</span> <span># [1,2,3] </span><span>print</span><span>(</span><span>"</span><span>Outside function:</span><span>"</span><span>,</span> <span>my_list</span><span>)</span> <span># [1,2,3,4] </span>
<span>def</span> <span>modify_mutable</span><span>(</span><span>lst</span><span>):</span>
    <span>lst</span><span>.</span><span>append</span><span>(</span><span>4</span><span>)</span>  <span># Modifying the original list object </span>    <span>print</span><span>(</span><span>"</span><span>Inside function:</span><span>"</span><span>,</span> <span>lst</span><span>)</span>

<span>my_list</span> <span>=</span> <span>[</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>]</span>
<span>modify_mutable</span><span>(</span><span>my_list</span><span>)</span> <span># [1,2,3] </span><span>print</span><span>(</span><span>"</span><span>Outside function:</span><span>"</span><span>,</span> <span>my_list</span><span>)</span> <span># [1,2,3,4] </span>
def modify_mutable(lst):
    lst.append(4)  # Modifying the original list object     print("Inside function:", lst)

my_list = [1, 2, 3]
modify_mutable(my_list) # [1,2,3] print("Outside function:", my_list) # [1,2,3,4]

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Numpy arrays (for numerical operations) 

<span>import</span> <span>numpy</span> <span>as</span> <span>np</span>
<span># Creating a 1D array </span><span>arr_1d</span> <span>=</span> <span>np</span><span>.</span><span>array</span><span>([</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>,</span> <span>4</span><span>,</span> <span>5</span><span>])</span>
<span># Creating a 2D array </span><span>arr_2d</span> <span>=</span> <span>np</span><span>.</span><span>array</span><span>([[</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>],</span> <span>[</span><span>4</span><span>,</span> <span>5</span><span>,</span> <span>6</span><span>]])</span>
<span># Creating an array filled with zeros </span><span>zeros</span> <span>=</span> <span>np</span><span>.</span><span>zeros</span><span>((</span><span>3</span><span>,</span> <span>4</span><span>))</span>
<span># Creating an array filled with ones </span><span>ones</span> <span>=</span> <span>np</span><span>.</span><span>ones</span><span>((</span><span>2</span><span>,</span> <span>3</span><span>))</span>
<span># Creating an array with a range of values </span><span>range_arr</span> <span>=</span> <span>np</span><span>.</span><span>arange</span><span>(</span><span>0</span><span>,</span> <span>10</span><span>,</span> <span>2</span><span>)</span>
<span># Creating an array with evenly spaced values </span><span>linspace_arr</span> <span>=</span> <span>np</span><span>.</span><span>linspace</span><span>(</span><span>0</span><span>,</span> <span>1</span><span>,</span> <span>5</span><span>)</span>
<span># Creating an identity matrix </span><span>identity_matrix</span> <span>=</span> <span>np</span><span>.</span><span>eye</span><span>(</span><span>3</span><span>)</span>
<span># Shape of the array </span><span>shape</span> <span>=</span> <span>arr_2d</span><span>.</span><span>shape</span>  <span># Output: (2, 3) </span>
<span># Size of the array (total number of elements) </span><span>size</span> <span>=</span> <span>arr_2d</span><span>.</span><span>size</span>  <span># Output: 6 </span>
<span># Element-wise addition </span><span>arr_add</span> <span>=</span> <span>arr_1d</span> <span>+</span> <span>5</span>  <span># Output: array([6, 7, 8, 9, 10]) </span>
<span># Element-wise subtraction </span><span>arr_sub</span> <span>=</span> <span>arr_1d</span> <span>-</span> <span>2</span>  <span># Output: array([ -1, 0, 1, 2, 3]) </span>
<span># Element-wise multiplication </span><span>arr_mul</span> <span>=</span> <span>arr_1d</span> <span>*</span> <span>2</span>  <span># Output: array([ 2, 4, 6, 8, 10]) </span>
<span># Element-wise division </span><span>arr_div</span> <span>=</span> <span>arr_1d</span> <span>/</span> <span>2</span>  <span># Output: array([0.5, 1. , 1.5, 2. , 2.5]) </span>
<span># Sum </span><span>total_sum</span> <span>=</span> <span>np</span><span>.</span><span>sum</span><span>(</span><span>arr_2d</span><span>)</span>  <span># Output: 21 </span>
<span># Mean </span><span>mean_value</span> <span>=</span> <span>np</span><span>.</span><span>mean</span><span>(</span><span>arr_2d</span><span>)</span>  <span># Output: 3.5 </span>
<span># Standard deviation </span><span>std_dev</span> <span>=</span> <span>np</span><span>.</span><span>std</span><span>(</span><span>arr_2d</span><span>)</span>  <span># Output: 1.707825127659933 </span>
<span># Maximum and minimum </span><span>max_value</span> <span>=</span> <span>np</span><span>.</span><span>max</span><span>(</span><span>arr_2d</span><span>)</span>  <span># Output: 6 </span><span>min_value</span> <span>=</span> <span>np</span><span>.</span><span>min</span><span>(</span><span>arr_2d</span><span>)</span>  <span># Output: 1 </span>
<span># Reshaping </span><span>reshaped_arr</span> <span>=</span> <span>arr_1d</span><span>.</span><span>reshape</span><span>((</span><span>5</span><span>,</span> <span>1</span><span>))</span>
<span># Flattening </span><span>flattened_arr</span> <span>=</span> <span>arr_2d</span><span>.</span><span>flatten</span><span>()</span>
<span># Transposing </span><span>transposed_arr</span> <span>=</span> <span>arr_2d</span><span>.</span><span>T</span>
<span># Indexing </span><span>element</span> <span>=</span> <span>arr_2d</span><span>[</span><span>1</span><span>,</span> <span>2</span><span>]</span>  <span># Output: 6 </span>
<span># Slicing </span><span>subarray</span> <span>=</span> <span>arr_2d</span><span>[</span><span>0</span><span>:</span><span>2</span><span>,</span> <span>1</span><span>:</span><span>3</span><span>]</span>  <span># Output: array([[2, 3], [5, 6]]) </span>
<span>import</span> <span>numpy</span> <span>as</span> <span>np</span>

<span># Creating a 1D array </span><span>arr_1d</span> <span>=</span> <span>np</span><span>.</span><span>array</span><span>([</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>,</span> <span>4</span><span>,</span> <span>5</span><span>])</span>

<span># Creating a 2D array </span><span>arr_2d</span> <span>=</span> <span>np</span><span>.</span><span>array</span><span>([[</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>],</span> <span>[</span><span>4</span><span>,</span> <span>5</span><span>,</span> <span>6</span><span>]])</span>

<span># Creating an array filled with zeros </span><span>zeros</span> <span>=</span> <span>np</span><span>.</span><span>zeros</span><span>((</span><span>3</span><span>,</span> <span>4</span><span>))</span>

<span># Creating an array filled with ones </span><span>ones</span> <span>=</span> <span>np</span><span>.</span><span>ones</span><span>((</span><span>2</span><span>,</span> <span>3</span><span>))</span>

<span># Creating an array with a range of values </span><span>range_arr</span> <span>=</span> <span>np</span><span>.</span><span>arange</span><span>(</span><span>0</span><span>,</span> <span>10</span><span>,</span> <span>2</span><span>)</span>

<span># Creating an array with evenly spaced values </span><span>linspace_arr</span> <span>=</span> <span>np</span><span>.</span><span>linspace</span><span>(</span><span>0</span><span>,</span> <span>1</span><span>,</span> <span>5</span><span>)</span>

<span># Creating an identity matrix </span><span>identity_matrix</span> <span>=</span> <span>np</span><span>.</span><span>eye</span><span>(</span><span>3</span><span>)</span>

<span># Shape of the array </span><span>shape</span> <span>=</span> <span>arr_2d</span><span>.</span><span>shape</span>  <span># Output: (2, 3) </span>
<span># Size of the array (total number of elements) </span><span>size</span> <span>=</span> <span>arr_2d</span><span>.</span><span>size</span>  <span># Output: 6 </span>
<span># Element-wise addition </span><span>arr_add</span> <span>=</span> <span>arr_1d</span> <span>+</span> <span>5</span>  <span># Output: array([6, 7, 8, 9, 10]) </span>
<span># Element-wise subtraction </span><span>arr_sub</span> <span>=</span> <span>arr_1d</span> <span>-</span> <span>2</span>  <span># Output: array([ -1, 0, 1, 2, 3]) </span>
<span># Element-wise multiplication </span><span>arr_mul</span> <span>=</span> <span>arr_1d</span> <span>*</span> <span>2</span>  <span># Output: array([ 2, 4, 6, 8, 10]) </span>
<span># Element-wise division </span><span>arr_div</span> <span>=</span> <span>arr_1d</span> <span>/</span> <span>2</span>  <span># Output: array([0.5, 1. , 1.5, 2. , 2.5]) </span>
<span># Sum </span><span>total_sum</span> <span>=</span> <span>np</span><span>.</span><span>sum</span><span>(</span><span>arr_2d</span><span>)</span>  <span># Output: 21 </span>
<span># Mean </span><span>mean_value</span> <span>=</span> <span>np</span><span>.</span><span>mean</span><span>(</span><span>arr_2d</span><span>)</span>  <span># Output: 3.5 </span>
<span># Standard deviation </span><span>std_dev</span> <span>=</span> <span>np</span><span>.</span><span>std</span><span>(</span><span>arr_2d</span><span>)</span>  <span># Output: 1.707825127659933 </span>
<span># Maximum and minimum </span><span>max_value</span> <span>=</span> <span>np</span><span>.</span><span>max</span><span>(</span><span>arr_2d</span><span>)</span>  <span># Output: 6 </span><span>min_value</span> <span>=</span> <span>np</span><span>.</span><span>min</span><span>(</span><span>arr_2d</span><span>)</span>  <span># Output: 1 </span>
<span># Reshaping </span><span>reshaped_arr</span> <span>=</span> <span>arr_1d</span><span>.</span><span>reshape</span><span>((</span><span>5</span><span>,</span> <span>1</span><span>))</span>

<span># Flattening </span><span>flattened_arr</span> <span>=</span> <span>arr_2d</span><span>.</span><span>flatten</span><span>()</span>

<span># Transposing </span><span>transposed_arr</span> <span>=</span> <span>arr_2d</span><span>.</span><span>T</span>

<span># Indexing </span><span>element</span> <span>=</span> <span>arr_2d</span><span>[</span><span>1</span><span>,</span> <span>2</span><span>]</span>  <span># Output: 6 </span>
<span># Slicing </span><span>subarray</span> <span>=</span> <span>arr_2d</span><span>[</span><span>0</span><span>:</span><span>2</span><span>,</span> <span>1</span><span>:</span><span>3</span><span>]</span>  <span># Output: array([[2, 3], [5, 6]]) </span>
import numpy as np

# Creating a 1D array arr_1d = np.array([1, 2, 3, 4, 5])

# Creating a 2D array arr_2d = np.array([[1, 2, 3], [4, 5, 6]])

# Creating an array filled with zeros zeros = np.zeros((3, 4))

# Creating an array filled with ones ones = np.ones((2, 3))

# Creating an array with a range of values range_arr = np.arange(0, 10, 2)

# Creating an array with evenly spaced values linspace_arr = np.linspace(0, 1, 5)

# Creating an identity matrix identity_matrix = np.eye(3)

# Shape of the array shape = arr_2d.shape  # Output: (2, 3) 
# Size of the array (total number of elements) size = arr_2d.size  # Output: 6 
# Element-wise addition arr_add = arr_1d + 5  # Output: array([6, 7, 8, 9, 10]) 
# Element-wise subtraction arr_sub = arr_1d - 2  # Output: array([ -1, 0, 1, 2, 3]) 
# Element-wise multiplication arr_mul = arr_1d * 2  # Output: array([ 2, 4, 6, 8, 10]) 
# Element-wise division arr_div = arr_1d / 2  # Output: array([0.5, 1. , 1.5, 2. , 2.5]) 
# Sum total_sum = np.sum(arr_2d)  # Output: 21 
# Mean mean_value = np.mean(arr_2d)  # Output: 3.5 
# Standard deviation std_dev = np.std(arr_2d)  # Output: 1.707825127659933 
# Maximum and minimum max_value = np.max(arr_2d)  # Output: 6 min_value = np.min(arr_2d)  # Output: 1 
# Reshaping reshaped_arr = arr_1d.reshape((5, 1))

# Flattening flattened_arr = arr_2d.flatten()

# Transposing transposed_arr = arr_2d.T

# Indexing element = arr_2d[1, 2]  # Output: 6 
# Slicing subarray = arr_2d[0:2, 1:3]  # Output: array([[2, 3], [5, 6]])

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Astype

It is a function in NumPy used to convert a numpy array to different data type. 

<span># Datatypes: np.int32,np.float32,np.float64,np.str_ </span><span>import</span> <span>numpy</span> <span>as</span> <span>np</span>
<span># Create an integer array </span><span>int_array</span> <span>=</span> <span>np</span><span>.</span><span>array</span><span>([</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>,</span> <span>4</span><span>,</span> <span>5</span><span>],</span> <span>dtype</span><span>=</span><span>np</span><span>.</span><span>int32</span><span>)</span>
<span># Convert to float </span><span>float_array</span> <span>=</span> <span>int_array</span><span>.</span><span>astype</span><span>(</span><span>np</span><span>.</span><span>float32</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>Original array:</span><span>"</span><span>,</span> <span>int_array</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>Converted array:</span><span>"</span><span>,</span> <span>float_array</span><span>)</span>
<span># Datatypes: np.int32,np.float32,np.float64,np.str_ </span><span>import</span> <span>numpy</span> <span>as</span> <span>np</span>

<span># Create an integer array </span><span>int_array</span> <span>=</span> <span>np</span><span>.</span><span>array</span><span>([</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>,</span> <span>4</span><span>,</span> <span>5</span><span>],</span> <span>dtype</span><span>=</span><span>np</span><span>.</span><span>int32</span><span>)</span>

<span># Convert to float </span><span>float_array</span> <span>=</span> <span>int_array</span><span>.</span><span>astype</span><span>(</span><span>np</span><span>.</span><span>float32</span><span>)</span>

<span>print</span><span>(</span><span>"</span><span>Original array:</span><span>"</span><span>,</span> <span>int_array</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>Converted array:</span><span>"</span><span>,</span> <span>float_array</span><span>)</span>
# Datatypes: np.int32,np.float32,np.float64,np.str_ import numpy as np

# Create an integer array int_array = np.array([1, 2, 3, 4, 5], dtype=np.int32)

# Convert to float float_array = int_array.astype(np.float32)

print("Original array:", int_array)
print("Converted array:", float_array)

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Reshape

It is a powerful tool for changing the shape of an array without altering its data 

<span>import</span> <span>numpy</span> <span>as</span> <span>np</span>
<span># Create a 1D array </span><span>array</span> <span>=</span> <span>np</span><span>.</span><span>arange</span><span>(</span><span>12</span><span>)</span>
<span># Reshape to a 2D array (3 rows x 4 columns) </span><span>reshaped_array</span> <span>=</span> <span>array</span><span>.</span><span>reshape</span><span>((</span><span>3</span><span>,</span> <span>4</span><span>))</span>
<span>import</span> <span>numpy</span> <span>as</span> <span>np</span>

<span># Create a 1D array </span><span>array</span> <span>=</span> <span>np</span><span>.</span><span>arange</span><span>(</span><span>12</span><span>)</span>

<span># Reshape to a 2D array (3 rows x 4 columns) </span><span>reshaped_array</span> <span>=</span> <span>array</span><span>.</span><span>reshape</span><span>((</span><span>3</span><span>,</span> <span>4</span><span>))</span>
import numpy as np

# Create a 1D array array = np.arange(12)

# Reshape to a 2D array (3 rows x 4 columns) reshaped_array = array.reshape((3, 4))

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Matplotlib 

<span>import</span> <span>numpy</span> <span>as</span> <span>np</span>
<span>import</span> <span>matplotlib.pyplot</span> <span>as</span> <span>plt</span>
<span># Create a random 2D array </span><span>data</span> <span>=</span> <span>np</span><span>.</span><span>random</span><span>.</span><span>rand</span><span>(</span><span>10</span><span>,</span> <span>10</span><span>)</span>
<span># Create a figure with a specific size and resolution </span><span>plt</span><span>.</span><span>figure</span><span>(</span><span>figsize</span><span>=</span><span>(</span><span>8</span><span>,</span> <span>6</span><span>),</span> <span>dpi</span><span>=</span><span>100</span><span>)</span>
<span># Display the 2D array as an image </span><span>plt</span><span>.</span><span>imshow</span><span>(</span><span>data</span><span>,</span> <span>cmap</span><span>=</span><span>'</span><span>viridis</span><span>'</span><span>,</span> <span>interpolation</span><span>=</span><span>'</span><span>nearest</span><span>'</span><span>)</span>
<span># Add a color bar to show the scale of values </span><span>plt</span><span>.</span><span>colorbar</span><span>()</span>
<span># Show the plot </span><span>plt</span><span>.</span><span>show</span><span>()</span>
<span>import</span> <span>numpy</span> <span>as</span> <span>np</span>
<span>import</span> <span>matplotlib.pyplot</span> <span>as</span> <span>plt</span>

<span># Create a random 2D array </span><span>data</span> <span>=</span> <span>np</span><span>.</span><span>random</span><span>.</span><span>rand</span><span>(</span><span>10</span><span>,</span> <span>10</span><span>)</span>

<span># Create a figure with a specific size and resolution </span><span>plt</span><span>.</span><span>figure</span><span>(</span><span>figsize</span><span>=</span><span>(</span><span>8</span><span>,</span> <span>6</span><span>),</span> <span>dpi</span><span>=</span><span>100</span><span>)</span>

<span># Display the 2D array as an image </span><span>plt</span><span>.</span><span>imshow</span><span>(</span><span>data</span><span>,</span> <span>cmap</span><span>=</span><span>'</span><span>viridis</span><span>'</span><span>,</span> <span>interpolation</span><span>=</span><span>'</span><span>nearest</span><span>'</span><span>)</span>

<span># Add a color bar to show the scale of values </span><span>plt</span><span>.</span><span>colorbar</span><span>()</span>

<span># Show the plot </span><span>plt</span><span>.</span><span>show</span><span>()</span>
import numpy as np
import matplotlib.pyplot as plt

# Create a random 2D array data = np.random.rand(10, 10)

# Create a figure with a specific size and resolution plt.figure(figsize=(8, 6), dpi=100)

# Display the 2D array as an image plt.imshow(data, cmap='viridis', interpolation='nearest')

# Add a color bar to show the scale of values plt.colorbar()

# Show the plot plt.show()

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Dictionary 

<span># Creating an empty dictionary # Maintains ascending order like map in cpp </span><span>my_dict</span> <span>=</span> <span>{}</span>
<span># Creating a dictionary with initial values </span><span>my_dict</span> <span>=</span> <span>{</span><span>'</span><span>name</span><span>'</span><span>:</span> <span>'</span><span>Alice</span><span>'</span><span>,</span> <span>'</span><span>age</span><span>'</span><span>:</span> <span>25</span><span>,</span> <span>'</span><span>city</span><span>'</span><span>:</span> <span>'</span><span>New York</span><span>'</span><span>}</span>
<span># Creating a dictionary using the dict() function </span><span>my_dict</span> <span>=</span> <span>dict</span><span>(</span><span>name</span><span>=</span><span>'</span><span>Alice</span><span>'</span><span>,</span> <span>age</span><span>=</span><span>25</span><span>,</span> <span>city</span><span>=</span><span>'</span><span>New York</span><span>'</span><span>)</span>
<span># Accessing a value by key </span><span>name</span> <span>=</span> <span>my_dict</span><span>[</span><span>'</span><span>name</span><span>'</span><span>]</span>  <span># Output: 'Alice' </span>
<span># Using the get() method to access a value </span><span>age</span> <span>=</span> <span>my_dict</span><span>.</span><span>get</span><span>(</span><span>'</span><span>age</span><span>'</span><span>)</span>  <span># Output: 25 </span><span>country</span> <span>=</span> <span>my_dict</span><span>.</span><span>get</span><span>(</span><span>'</span><span>country</span><span>'</span><span>)</span>  <span># Output: None </span>
<span># Adding a new key-value pair </span><span>my_dict</span><span>[</span><span>'</span><span>email</span><span>'</span><span>]</span> <span>=</span> <span>'</span><span>alice@example.com</span><span>'</span>
<span># Updating an existing value </span><span>my_dict</span><span>[</span><span>'</span><span>age</span><span>'</span><span>]</span> <span>=</span> <span>26</span>
<span># Removing a key-value pair using pop() </span><span>age</span> <span>=</span> <span>my_dict</span><span>.</span><span>pop</span><span>(</span><span>'</span><span>age</span><span>'</span><span>)</span>  <span># Removes 'age' and returns its value </span>
<span># Getting all keys in the dictionary </span><span>keys</span> <span>=</span> <span>my_dict</span><span>.</span><span>keys</span><span>()</span>  <span># Output: dict_keys(['name', 'email']) </span>
<span># Getting all values in the dictionary </span><span>values</span> <span>=</span> <span>my_dict</span><span>.</span><span>values</span><span>()</span>  <span># Output: dict_values(['Alice', 'alice@example.com']) </span>
<span># Iterating over keys </span><span>for</span> <span>key</span> <span>in</span> <span>my_dict</span><span>:</span>
    <span>print</span><span>(</span><span>key</span><span>)</span>
<span># Iterating over values </span><span>for</span> <span>value</span> <span>in</span> <span>my_dict</span><span>.</span><span>values</span><span>():</span>
    <span>print</span><span>(</span><span>value</span><span>)</span>
<span># Iterating over key-value pairs </span><span>for</span> <span>key</span><span>,</span> <span>value</span> <span>in</span> <span>my_dict</span><span>.</span><span>items</span><span>():</span>
    <span>print</span><span>(</span><span>f</span><span>"</span><span>{</span><span>key</span><span>}</span><span>: </span><span>{</span><span>value</span><span>}</span><span>"</span><span>)</span>
<span># Creating an empty dictionary # Maintains ascending order like map in cpp </span><span>my_dict</span> <span>=</span> <span>{}</span>

<span># Creating a dictionary with initial values </span><span>my_dict</span> <span>=</span> <span>{</span><span>'</span><span>name</span><span>'</span><span>:</span> <span>'</span><span>Alice</span><span>'</span><span>,</span> <span>'</span><span>age</span><span>'</span><span>:</span> <span>25</span><span>,</span> <span>'</span><span>city</span><span>'</span><span>:</span> <span>'</span><span>New York</span><span>'</span><span>}</span>

<span># Creating a dictionary using the dict() function </span><span>my_dict</span> <span>=</span> <span>dict</span><span>(</span><span>name</span><span>=</span><span>'</span><span>Alice</span><span>'</span><span>,</span> <span>age</span><span>=</span><span>25</span><span>,</span> <span>city</span><span>=</span><span>'</span><span>New York</span><span>'</span><span>)</span>

<span># Accessing a value by key </span><span>name</span> <span>=</span> <span>my_dict</span><span>[</span><span>'</span><span>name</span><span>'</span><span>]</span>  <span># Output: 'Alice' </span>
<span># Using the get() method to access a value </span><span>age</span> <span>=</span> <span>my_dict</span><span>.</span><span>get</span><span>(</span><span>'</span><span>age</span><span>'</span><span>)</span>  <span># Output: 25 </span><span>country</span> <span>=</span> <span>my_dict</span><span>.</span><span>get</span><span>(</span><span>'</span><span>country</span><span>'</span><span>)</span>  <span># Output: None </span>
<span># Adding a new key-value pair </span><span>my_dict</span><span>[</span><span>'</span><span>email</span><span>'</span><span>]</span> <span>=</span> <span>'</span><span>alice@example.com</span><span>'</span>

<span># Updating an existing value </span><span>my_dict</span><span>[</span><span>'</span><span>age</span><span>'</span><span>]</span> <span>=</span> <span>26</span>

<span># Removing a key-value pair using pop() </span><span>age</span> <span>=</span> <span>my_dict</span><span>.</span><span>pop</span><span>(</span><span>'</span><span>age</span><span>'</span><span>)</span>  <span># Removes 'age' and returns its value </span>
<span># Getting all keys in the dictionary </span><span>keys</span> <span>=</span> <span>my_dict</span><span>.</span><span>keys</span><span>()</span>  <span># Output: dict_keys(['name', 'email']) </span>
<span># Getting all values in the dictionary </span><span>values</span> <span>=</span> <span>my_dict</span><span>.</span><span>values</span><span>()</span>  <span># Output: dict_values(['Alice', 'alice@example.com']) </span>
<span># Iterating over keys </span><span>for</span> <span>key</span> <span>in</span> <span>my_dict</span><span>:</span>
    <span>print</span><span>(</span><span>key</span><span>)</span>

<span># Iterating over values </span><span>for</span> <span>value</span> <span>in</span> <span>my_dict</span><span>.</span><span>values</span><span>():</span>
    <span>print</span><span>(</span><span>value</span><span>)</span>

<span># Iterating over key-value pairs </span><span>for</span> <span>key</span><span>,</span> <span>value</span> <span>in</span> <span>my_dict</span><span>.</span><span>items</span><span>():</span>
    <span>print</span><span>(</span><span>f</span><span>"</span><span>{</span><span>key</span><span>}</span><span>: </span><span>{</span><span>value</span><span>}</span><span>"</span><span>)</span>
# Creating an empty dictionary # Maintains ascending order like map in cpp my_dict = {}

# Creating a dictionary with initial values my_dict = {'name': 'Alice', 'age': 25, 'city': 'New York'}

# Creating a dictionary using the dict() function my_dict = dict(name='Alice', age=25, city='New York')

# Accessing a value by key name = my_dict['name']  # Output: 'Alice' 
# Using the get() method to access a value age = my_dict.get('age')  # Output: 25 country = my_dict.get('country')  # Output: None 
# Adding a new key-value pair my_dict['email'] = 'alice@example.com'

# Updating an existing value my_dict['age'] = 26

# Removing a key-value pair using pop() age = my_dict.pop('age')  # Removes 'age' and returns its value 
# Getting all keys in the dictionary keys = my_dict.keys()  # Output: dict_keys(['name', 'email']) 
# Getting all values in the dictionary values = my_dict.values()  # Output: dict_values(['Alice', 'alice@example.com']) 
# Iterating over keys for key in my_dict:
    print(key)

# Iterating over values for value in my_dict.values():
    print(value)

# Iterating over key-value pairs for key, value in my_dict.items():
    print(f"{key}: {value}")

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Defaultdict 

<span>from</span> <span>collections</span> <span>import</span> <span>defaultdict</span>
<span>d</span> <span>=</span> <span>defaultdict</span><span>(</span><span>int</span><span>)</span>
<span># Initializes 0 to non-existent keys </span><span>d</span><span>[</span><span>'</span><span>apple</span><span>'</span><span>]</span> <span>+=</span> <span>1</span>
<span>d</span><span>[</span><span>'</span><span>banana</span><span>'</span><span>]</span> <span>+=</span> <span>2</span>
<span>from</span> <span>collections</span> <span>import</span> <span>defaultdict</span>

<span>d</span> <span>=</span> <span>defaultdict</span><span>(</span><span>int</span><span>)</span>

<span># Initializes 0 to non-existent keys </span><span>d</span><span>[</span><span>'</span><span>apple</span><span>'</span><span>]</span> <span>+=</span> <span>1</span>
<span>d</span><span>[</span><span>'</span><span>banana</span><span>'</span><span>]</span> <span>+=</span> <span>2</span>
from collections import defaultdict

d = defaultdict(int)

# Initializes 0 to non-existent keys d['apple'] += 1
d['banana'] += 2

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Set 

<span># Creating an empty set </span><span>my_set</span> <span>=</span> <span>set</span><span>()</span>
<span># Creating a set with initial values </span><span>my_set</span> <span>=</span> <span>{</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>,</span> <span>4</span><span>,</span> <span>5</span><span>}</span>
<span># Creating a set from a list </span><span>my_list</span> <span>=</span> <span>[</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>,</span> <span>4</span><span>,</span> <span>5</span><span>]</span>
<span>my_set</span> <span>=</span> <span>set</span><span>(</span><span>my_list</span><span>)</span>
<span># Creating a set from a string </span><span>my_set</span> <span>=</span> <span>set</span><span>(</span><span>'</span><span>hello</span><span>'</span><span>)</span>  <span># Output: {'e', 'h', 'l', 'o'} </span>
<span># Adding an element to a set </span><span>my_set</span><span>.</span><span>add</span><span>(</span><span>6</span><span>)</span>  <span># my_set becomes {1, 2, 3, 4, 5, 6} </span>
<span># Removing an element from a set (raises KeyError if not found) </span><span>my_set</span><span>.</span><span>remove</span><span>(</span><span>3</span><span>)</span>  <span># my_set becomes {1, 2, 4, 5, 6} </span>
<span># Removing and returning an arbitrary element from the set </span><span>element</span> <span>=</span> <span>my_set</span><span>.</span><span>pop</span><span>()</span>  <span># Returns and removes an arbitrary element </span>
<span># Creating an empty set </span><span>my_set</span> <span>=</span> <span>set</span><span>()</span>

<span># Creating a set with initial values </span><span>my_set</span> <span>=</span> <span>{</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>,</span> <span>4</span><span>,</span> <span>5</span><span>}</span>

<span># Creating a set from a list </span><span>my_list</span> <span>=</span> <span>[</span><span>1</span><span>,</span> <span>2</span><span>,</span> <span>3</span><span>,</span> <span>4</span><span>,</span> <span>5</span><span>]</span>
<span>my_set</span> <span>=</span> <span>set</span><span>(</span><span>my_list</span><span>)</span>

<span># Creating a set from a string </span><span>my_set</span> <span>=</span> <span>set</span><span>(</span><span>'</span><span>hello</span><span>'</span><span>)</span>  <span># Output: {'e', 'h', 'l', 'o'} </span>
<span># Adding an element to a set </span><span>my_set</span><span>.</span><span>add</span><span>(</span><span>6</span><span>)</span>  <span># my_set becomes {1, 2, 3, 4, 5, 6} </span>
<span># Removing an element from a set (raises KeyError if not found) </span><span>my_set</span><span>.</span><span>remove</span><span>(</span><span>3</span><span>)</span>  <span># my_set becomes {1, 2, 4, 5, 6} </span>
<span># Removing and returning an arbitrary element from the set </span><span>element</span> <span>=</span> <span>my_set</span><span>.</span><span>pop</span><span>()</span>  <span># Returns and removes an arbitrary element </span>
# Creating an empty set my_set = set()

# Creating a set with initial values my_set = {1, 2, 3, 4, 5}

# Creating a set from a list my_list = [1, 2, 3, 4, 5]
my_set = set(my_list)

# Creating a set from a string my_set = set('hello')  # Output: {'e', 'h', 'l', 'o'} 
# Adding an element to a set my_set.add(6)  # my_set becomes {1, 2, 3, 4, 5, 6} 
# Removing an element from a set (raises KeyError if not found) my_set.remove(3)  # my_set becomes {1, 2, 4, 5, 6} 
# Removing and returning an arbitrary element from the set element = my_set.pop()  # Returns and removes an arbitrary element

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String 

<span># Single quotes </span><span>str1</span> <span>=</span> <span>'</span><span>Hello</span><span>'</span>
<span># Double quotes </span><span>str2</span> <span>=</span> <span>"</span><span>World</span><span>"</span>
<span># Triple quotes for multi-line strings </span><span>str3</span> <span>=</span> <span>'''</span><span>This is a multi-line string.</span><span>'''</span>
<span># Raw strings (ignores escape sequences) </span><span>raw_str</span> <span>=</span> <span>r</span><span>'</span><span>C:\Users\Name</span><span>'</span>
<span>str1</span> <span>=</span> <span>'</span><span>Hello</span><span>'</span>
<span># Accessing a single character </span><span>char</span> <span>=</span> <span>str1</span><span>[</span><span>1</span><span>]</span>  <span># 'e' </span>
<span># Accessing a substring (slicing) </span><span>substring</span> <span>=</span> <span>str1</span><span>[</span><span>1</span><span>:</span><span>4</span><span>]</span>  <span># 'ell' </span>
<span># Negative indexing </span><span>last_char</span> <span>=</span> <span>str1</span><span>[</span><span>-</span><span>1</span><span>]</span>  <span># 'o' </span>
<span># Using + operator </span><span>concatenated</span> <span>=</span> <span>'</span><span>Hello</span><span>'</span> <span>+</span> <span>'</span><span> </span><span>'</span> <span>+</span> <span>'</span><span>World</span><span>'</span>  <span># 'Hello World' </span>
<span># Using join method </span><span>words</span> <span>=</span> <span>[</span><span>'</span><span>Hello</span><span>'</span><span>,</span> <span>'</span><span>World</span><span>'</span><span>]</span>
<span>concatenated</span> <span>=</span> <span>'</span><span> </span><span>'</span><span>.</span><span>join</span><span>(</span><span>words</span><span>)</span>  <span># 'Hello World' </span>
<span>name</span> <span>=</span> <span>'</span><span>Alice</span><span>'</span>
<span>age</span> <span>=</span> <span>25</span>
<span># String formatting </span><span>formatted_str</span> <span>=</span> <span>f</span><span>'</span><span>My name is </span><span>{</span><span>name</span><span>}</span><span> and I am </span><span>{</span><span>age</span><span>}</span><span> years old.</span><span>'</span>
<span># Convert to uppercase </span><span>upper_str</span> <span>=</span> <span>str1</span><span>.</span><span>upper</span><span>()</span>  <span># 'HELLO WORLD' </span>
<span># Convert to lowercase </span><span>lower_str</span> <span>=</span> <span>str1</span><span>.</span><span>lower</span><span>()</span>  <span># 'hello world' </span>
<span># Convert to capitalize </span><span>capital_str</span> <span>=</span> <span>str1</span><span>.</span><span>capitalize</span><span>()</span>  <span># 'Hello world' </span>
<span>str1</span> <span>=</span> <span>'</span><span> Hello World </span><span>'</span>
<span># Remove leading and trailing whitespace </span><span>trimmed</span> <span>=</span> <span>str1</span><span>.</span><span>strip</span><span>()</span>  <span># 'Hello World' </span>
<span>str1</span> <span>=</span> <span>'</span><span>Hello World Python</span><span>'</span>
<span># Split the string into a list of substrings </span><span>split_list</span> <span>=</span> <span>str1</span><span>.</span><span>split</span><span>()</span>  <span># ['Hello', 'World', 'Python'] </span>
<span># Split the string with a specific delimiter </span><span>split_list</span> <span>=</span> <span>str1</span><span>.</span><span>split</span><span>(</span><span>'</span><span> </span><span>'</span><span>)</span>  <span># ['Hello', 'World', 'Python'] </span>
<span># Join a list of strings into a single string </span><span>joined_str</span> <span>=</span> <span>'</span><span> </span><span>'</span><span>.</span><span>join</span><span>(</span><span>split_list</span><span>)</span>  <span># 'Hello World Python' </span>
<span>str1</span> <span>=</span> <span>'</span><span>Hello World</span><span>'</span>
<span># Find the position of a substring </span><span>pos</span> <span>=</span> <span>str1</span><span>.</span><span>find</span><span>(</span><span>'</span><span>World</span><span>'</span><span>)</span>  <span># 6 </span>
<span>str1</span> <span>=</span> <span>'</span><span>Hello123</span><span>'</span>
<span># Check if all characters are alphanumeric </span><span>is_alnum</span> <span>=</span> <span>str1</span><span>.</span><span>isalnum</span><span>()</span>  <span># True </span>
<span># Check if all characters are alphabetic </span><span>is_alpha</span> <span>=</span> <span>str1</span><span>.</span><span>isalpha</span><span>()</span>  <span># False </span>
<span># Check if all characters are digits </span><span>is_digit</span> <span>=</span> <span>str1</span><span>.</span><span>isdigit</span><span>()</span>  <span># False </span>
<span># Check if all characters are lowercase </span><span>is_lower</span> <span>=</span> <span>str1</span><span>.</span><span>islower</span><span>()</span>  <span># False </span>
<span># Check if all characters are uppercase </span><span>is_upper</span> <span>=</span> <span>str1</span><span>.</span><span>isupper</span><span>()</span>  <span># False </span>
<span># Single quotes </span><span>str1</span> <span>=</span> <span>'</span><span>Hello</span><span>'</span>

<span># Double quotes </span><span>str2</span> <span>=</span> <span>"</span><span>World</span><span>"</span>

<span># Triple quotes for multi-line strings </span><span>str3</span> <span>=</span> <span>'''</span><span>This is a multi-line string.</span><span>'''</span>

<span># Raw strings (ignores escape sequences) </span><span>raw_str</span> <span>=</span> <span>r</span><span>'</span><span>C:\Users\Name</span><span>'</span>

<span>str1</span> <span>=</span> <span>'</span><span>Hello</span><span>'</span>

<span># Accessing a single character </span><span>char</span> <span>=</span> <span>str1</span><span>[</span><span>1</span><span>]</span>  <span># 'e' </span>
<span># Accessing a substring (slicing) </span><span>substring</span> <span>=</span> <span>str1</span><span>[</span><span>1</span><span>:</span><span>4</span><span>]</span>  <span># 'ell' </span>
<span># Negative indexing </span><span>last_char</span> <span>=</span> <span>str1</span><span>[</span><span>-</span><span>1</span><span>]</span>  <span># 'o' </span>
<span># Using + operator </span><span>concatenated</span> <span>=</span> <span>'</span><span>Hello</span><span>'</span> <span>+</span> <span>'</span><span> </span><span>'</span> <span>+</span> <span>'</span><span>World</span><span>'</span>  <span># 'Hello World' </span>
<span># Using join method </span><span>words</span> <span>=</span> <span>[</span><span>'</span><span>Hello</span><span>'</span><span>,</span> <span>'</span><span>World</span><span>'</span><span>]</span>
<span>concatenated</span> <span>=</span> <span>'</span><span> </span><span>'</span><span>.</span><span>join</span><span>(</span><span>words</span><span>)</span>  <span># 'Hello World' </span>
<span>name</span> <span>=</span> <span>'</span><span>Alice</span><span>'</span>
<span>age</span> <span>=</span> <span>25</span>

<span># String formatting </span><span>formatted_str</span> <span>=</span> <span>f</span><span>'</span><span>My name is </span><span>{</span><span>name</span><span>}</span><span> and I am </span><span>{</span><span>age</span><span>}</span><span> years old.</span><span>'</span>

<span># Convert to uppercase </span><span>upper_str</span> <span>=</span> <span>str1</span><span>.</span><span>upper</span><span>()</span>  <span># 'HELLO WORLD' </span>
<span># Convert to lowercase </span><span>lower_str</span> <span>=</span> <span>str1</span><span>.</span><span>lower</span><span>()</span>  <span># 'hello world' </span>
<span># Convert to capitalize </span><span>capital_str</span> <span>=</span> <span>str1</span><span>.</span><span>capitalize</span><span>()</span>  <span># 'Hello world' </span>
<span>str1</span> <span>=</span> <span>'</span><span> Hello World </span><span>'</span>

<span># Remove leading and trailing whitespace </span><span>trimmed</span> <span>=</span> <span>str1</span><span>.</span><span>strip</span><span>()</span>  <span># 'Hello World' </span>
<span>str1</span> <span>=</span> <span>'</span><span>Hello World Python</span><span>'</span>

<span># Split the string into a list of substrings </span><span>split_list</span> <span>=</span> <span>str1</span><span>.</span><span>split</span><span>()</span>  <span># ['Hello', 'World', 'Python'] </span>
<span># Split the string with a specific delimiter </span><span>split_list</span> <span>=</span> <span>str1</span><span>.</span><span>split</span><span>(</span><span>'</span><span> </span><span>'</span><span>)</span>  <span># ['Hello', 'World', 'Python'] </span>
<span># Join a list of strings into a single string </span><span>joined_str</span> <span>=</span> <span>'</span><span> </span><span>'</span><span>.</span><span>join</span><span>(</span><span>split_list</span><span>)</span>  <span># 'Hello World Python' </span>
<span>str1</span> <span>=</span> <span>'</span><span>Hello World</span><span>'</span>

<span># Find the position of a substring </span><span>pos</span> <span>=</span> <span>str1</span><span>.</span><span>find</span><span>(</span><span>'</span><span>World</span><span>'</span><span>)</span>  <span># 6 </span>

<span>str1</span> <span>=</span> <span>'</span><span>Hello123</span><span>'</span>

<span># Check if all characters are alphanumeric </span><span>is_alnum</span> <span>=</span> <span>str1</span><span>.</span><span>isalnum</span><span>()</span>  <span># True </span>
<span># Check if all characters are alphabetic </span><span>is_alpha</span> <span>=</span> <span>str1</span><span>.</span><span>isalpha</span><span>()</span>  <span># False </span>
<span># Check if all characters are digits </span><span>is_digit</span> <span>=</span> <span>str1</span><span>.</span><span>isdigit</span><span>()</span>  <span># False </span>
<span># Check if all characters are lowercase </span><span>is_lower</span> <span>=</span> <span>str1</span><span>.</span><span>islower</span><span>()</span>  <span># False </span>
<span># Check if all characters are uppercase </span><span>is_upper</span> <span>=</span> <span>str1</span><span>.</span><span>isupper</span><span>()</span>  <span># False </span>
# Single quotes str1 = 'Hello'

# Double quotes str2 = "World"

# Triple quotes for multi-line strings str3 = '''This is a multi-line string.'''

# Raw strings (ignores escape sequences) raw_str = r'C:\Users\Name'

str1 = 'Hello'

# Accessing a single character char = str1[1]  # 'e' 
# Accessing a substring (slicing) substring = str1[1:4]  # 'ell' 
# Negative indexing last_char = str1[-1]  # 'o' 
# Using + operator concatenated = 'Hello' + ' ' + 'World'  # 'Hello World' 
# Using join method words = ['Hello', 'World']
concatenated = ' '.join(words)  # 'Hello World' 
name = 'Alice'
age = 25

# String formatting formatted_str = f'My name is {name} and I am {age} years old.'

# Convert to uppercase upper_str = str1.upper()  # 'HELLO WORLD' 
# Convert to lowercase lower_str = str1.lower()  # 'hello world' 
# Convert to capitalize capital_str = str1.capitalize()  # 'Hello world' 
str1 = ' Hello World '

# Remove leading and trailing whitespace trimmed = str1.strip()  # 'Hello World' 
str1 = 'Hello World Python'

# Split the string into a list of substrings split_list = str1.split()  # ['Hello', 'World', 'Python'] 
# Split the string with a specific delimiter split_list = str1.split(' ')  # ['Hello', 'World', 'Python'] 
# Join a list of strings into a single string joined_str = ' '.join(split_list)  # 'Hello World Python' 
str1 = 'Hello World'

# Find the position of a substring pos = str1.find('World')  # 6 

str1 = 'Hello123'

# Check if all characters are alphanumeric is_alnum = str1.isalnum()  # True 
# Check if all characters are alphabetic is_alpha = str1.isalpha()  # False 
# Check if all characters are digits is_digit = str1.isdigit()  # False 
# Check if all characters are lowercase is_lower = str1.islower()  # False 
# Check if all characters are uppercase is_upper = str1.isupper()  # False

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原文链接：Python Code Snippets

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