Python – Getting started (7 Part Series)

1 Python – First steps
2 Python – Data types
… 3 more parts…
3 Python – Variables
4 Python – Calculator sample
5 Python – Conditionals
6 Python – Functions and variable scopes
7 Python – Lists and loops

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Using conditions

If you need to check some conditions to execute your code, you can use if statements. You can take a look on Python Operators to know more about all types of operators for python.

<span>print</span><span>(</span><span>"</span><span>Please, enter your genre:</span><span>"</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>1 - Male</span><span>"</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>2 - Female</span><span>"</span><span>)</span>
<span>genre</span> <span>=</span> <span>int</span><span>(</span><span>input</span><span>())</span>
<span>if</span> <span>genre</span> <span>==</span> <span>1</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a men</span><span>"</span><span>)</span>
<span>if</span> <span>genre</span> <span>==</span> <span>2</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a women</span><span>"</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>Please, enter your genre:</span><span>"</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>1 - Male</span><span>"</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>2 - Female</span><span>"</span><span>)</span>
<span>genre</span> <span>=</span> <span>int</span><span>(</span><span>input</span><span>())</span>

<span>if</span> <span>genre</span> <span>==</span> <span>1</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a men</span><span>"</span><span>)</span>
<span>if</span> <span>genre</span> <span>==</span> <span>2</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a women</span><span>"</span><span>)</span>
print("Please, enter your genre:")
print("1 - Male")
print("2 - Female")
genre = int(input())

if genre == 1:
  print("You're a men")
if genre == 2:
  print("You're a women")

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It’s important to know that after each statement we have to indent the statement content. Usually, two blank spaces is the default indent mark for python but you can customize it. It means that all indent code will be execute only if it satisfies the if condition. So, the two pieces of code below will be differents.

<span>if</span> <span>genre</span> <span>==</span> <span>1</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a men</span><span>"</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>my sample string</span><span>"</span><span>)</span> <span># it will be always printed </span><span>if</span> <span>genre</span> <span>==</span> <span>2</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a women</span><span>"</span><span>)</span>
<span>if</span> <span>genre</span> <span>==</span> <span>1</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a men</span><span>"</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>my sample string</span><span>"</span><span>)</span> <span># it will be always printed </span><span>if</span> <span>genre</span> <span>==</span> <span>2</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a women</span><span>"</span><span>)</span>
if genre == 1:
  print("You're a men")
print("my sample string") # it will be always printed if genre == 2:
  print("You're a women")

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<span>if</span> <span>genre</span> <span>==</span> <span>1</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a men</span><span>"</span><span>)</span>
  <span>print</span><span>(</span><span>"</span><span>my sample string</span><span>"</span><span>)</span> <span># it will be only printed when genre equals 1 </span><span>if</span> <span>genre</span> <span>==</span> <span>2</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a women</span><span>"</span><span>)</span>
<span>if</span> <span>genre</span> <span>==</span> <span>1</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a men</span><span>"</span><span>)</span>
  <span>print</span><span>(</span><span>"</span><span>my sample string</span><span>"</span><span>)</span> <span># it will be only printed when genre equals 1 </span><span>if</span> <span>genre</span> <span>==</span> <span>2</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a women</span><span>"</span><span>)</span>
if genre == 1:
  print("You're a men")
  print("my sample string") # it will be only printed when genre equals 1 if genre == 2:
  print("You're a women")

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Here we have another exemple to check if a person is an adult, child or a teenager.

<span>print</span><span>(</span><span>"</span><span>Please, enter your age:</span><span>"</span><span>)</span>
<span>age</span> <span>=</span> <span>int</span><span>(</span><span>input</span><span>())</span>
<span>if</span> <span>age</span> <span><</span> <span>13</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a child</span><span>"</span><span>)</span>
<span>elif</span> <span>age</span> <span><</span> <span>18</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a teenager</span><span>"</span><span>)</span>
<span>else</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re an adult</span><span>"</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>Please, enter your age:</span><span>"</span><span>)</span>
<span>age</span> <span>=</span> <span>int</span><span>(</span><span>input</span><span>())</span>

<span>if</span> <span>age</span> <span><</span> <span>13</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a child</span><span>"</span><span>)</span>
<span>elif</span> <span>age</span> <span><</span> <span>18</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re a teenager</span><span>"</span><span>)</span>
<span>else</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>You</span><span>'</span><span>re an adult</span><span>"</span><span>)</span>
print("Please, enter your age:")
age = int(input())

if age < 13:
  print("You're a child")
elif age < 18:
  print("You're a teenager")
else:
  print("You're an adult")

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You can combine multi conditions using logical operators like and and or

<span>print</span><span>(</span><span>"</span><span>Please, enter your genre:</span><span>"</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>1 - Male</span><span>"</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>2 - Female</span><span>"</span><span>)</span>
<span>genre</span> <span>=</span> <span>int</span><span>(</span><span>input</span><span>())</span>
<span>print</span><span>(</span><span>"</span><span>Please, enter your age:</span><span>"</span><span>)</span>
<span>age</span> <span>=</span> <span>int</span><span>(</span><span>input</span><span>())</span>
<span>if</span> <span>genre</span> <span>==</span> <span>1</span> <span>and</span> <span>age</span> <span>>=</span> <span>12</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>Your birthday</span><span>'</span><span>s gift will be a playstation</span><span>"</span><span>)</span>
<span>elif</span> <span>genre</span> <span>==</span> <span>2</span> <span>and</span> <span>age</span> <span><</span> <span>10</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>Your birthday</span><span>'</span><span>s gift will be a doll</span><span>"</span><span>)</span>
<span>else</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>Your birthday</span><span>'</span><span>s gift will be a surprise</span><span>"</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>Please, enter your genre:</span><span>"</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>1 - Male</span><span>"</span><span>)</span>
<span>print</span><span>(</span><span>"</span><span>2 - Female</span><span>"</span><span>)</span>
<span>genre</span> <span>=</span> <span>int</span><span>(</span><span>input</span><span>())</span>

<span>print</span><span>(</span><span>"</span><span>Please, enter your age:</span><span>"</span><span>)</span>
<span>age</span> <span>=</span> <span>int</span><span>(</span><span>input</span><span>())</span>

<span>if</span> <span>genre</span> <span>==</span> <span>1</span> <span>and</span> <span>age</span> <span>>=</span> <span>12</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>Your birthday</span><span>'</span><span>s gift will be a playstation</span><span>"</span><span>)</span>
<span>elif</span> <span>genre</span> <span>==</span> <span>2</span> <span>and</span> <span>age</span> <span><</span> <span>10</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>Your birthday</span><span>'</span><span>s gift will be a doll</span><span>"</span><span>)</span>
<span>else</span><span>:</span>
  <span>print</span><span>(</span><span>"</span><span>Your birthday</span><span>'</span><span>s gift will be a surprise</span><span>"</span><span>)</span>
print("Please, enter your genre:")
print("1 - Male")
print("2 - Female")
genre = int(input())

print("Please, enter your age:")
age = int(input())

if genre == 1 and age >= 12:
  print("Your birthday's gift will be a playstation")
elif genre == 2 and age < 10:
  print("Your birthday's gift will be a doll")
else:
  print("Your birthday's gift will be a surprise")

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Typos or suggestions?

<<<<<<< HEAD

If you’ve found a typo, a sentence that could be improved or anything else that should be updated on this blog post, you can access it through a git repository and make a pull request. If you feel comfortable with github, instead of posting a comment, please go directly to https://github.com/campelo/documentation and open a new pull request with your changes.

If you’ve found a typo, a sentence that could be improved or anything else that should be updated on this blog post, you can access it through a git repository and make a pull request. If you feel comfortable with github, instead of posting a comment, please go directly to https://github.com/campelo/documentation and open a new pull request with your changes.

origin/master

Python – Getting started (7 Part Series)

1 Python – First steps
2 Python – Data types
… 3 more parts…
3 Python – Variables
4 Python – Calculator sample
5 Python – Conditionals
6 Python – Functions and variable scopes
7 Python – Lists and loops

原文链接：Python – Conditionals