Python String isdecimal()

The Python String isdecimal() method is a built-in function that returns true if all the characters in a string are decimal. If one of the characters is not decimal in the string, it returns false.

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In this article, we will learn about the Python String isdecimal() method with the help of examples.

isdecimal() Syntax

The Syntax of isdecimal() method is:

<span>string</span><span>.</span><span>isdecimal</span><span>()</span>
<span>string</span><span>.</span><span>isdecimal</span><span>()</span>
string.isdecimal()

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isdecimal() Parameters

The isdecimal() method does not take any parameters.

isdecimal() Return Value

The isdecimal() method returns

• True if all the characters in a string are valid decimal characters.
• False if one or more characters in a string are not decimal characters.

Example 1: Working of isdecimal()

<span># Python3 program to demonstrate the use # of isdecimal() </span>
<span>s</span> <span>=</span> <span>"12345"</span>
<span>print</span><span>(</span><span>s</span><span>.</span><span>isdecimal</span><span>())</span>
<span># contains alphabets </span><span>s</span> <span>=</span> <span>"123Hello123"</span>
<span>print</span><span>(</span><span>s</span><span>.</span><span>isdecimal</span><span>())</span>
<span># contains numbers and spaces </span><span>s</span> <span>=</span> <span>"12345 6789"</span>
<span>print</span><span>(</span><span>s</span><span>.</span><span>isdecimal</span><span>())</span>
<span># Python3 program to demonstrate the use # of isdecimal() </span>
<span>s</span> <span>=</span> <span>"12345"</span>
<span>print</span><span>(</span><span>s</span><span>.</span><span>isdecimal</span><span>())</span>

<span># contains alphabets </span><span>s</span> <span>=</span> <span>"123Hello123"</span>
<span>print</span><span>(</span><span>s</span><span>.</span><span>isdecimal</span><span>())</span>

<span># contains numbers and spaces </span><span>s</span> <span>=</span> <span>"12345 6789"</span>
<span>print</span><span>(</span><span>s</span><span>.</span><span>isdecimal</span><span>())</span>

# Python3 program to demonstrate the use # of isdecimal() 
s = "12345"
print(s.isdecimal())

# contains alphabets s = "123Hello123"
print(s.isdecimal())

# contains numbers and spaces s = "12345 6789"
print(s.isdecimal())

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Output

<span>True</span>
<span>False</span>
<span>False</span>
<span>True</span>
<span>False</span>
<span>False</span>
True
False
False

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Example 2: String Containing digits and Numeric Characters

The superscript and subscript are considered as digit characters and not decimals. If the string contains subscript or superscript the isdecimal() method will returns False.

Similarly, the roman numbers, currencies and fractions are considered as numeric numbers and not decimals. The isdecimal() will return False if it finds these characters.

It is recommended to use isdigit() method and isnumeric() method to check if the characters are valid digits and numeric characters respectively.

<span># Python3 program to demonstrate the use # of isdecimal() </span>
<span># vaid decimal </span><span>s</span> <span>=</span> <span>'12345'</span>
<span>print</span><span>(</span><span>s</span><span>.</span><span>isdecimal</span><span>())</span>
<span># in case of digit #s = '²123' </span><span>s</span> <span>=</span> <span>'</span><span>\u00B2</span><span>123'</span>
<span>print</span><span>(</span><span>s</span><span>.</span><span>isdecimal</span><span>())</span>
<span># incase of numeric # s = '½' </span><span>s</span> <span>=</span> <span>'</span><span>\u00BD</span><span>'</span>
<span>print</span><span>(</span><span>s</span><span>.</span><span>isdecimal</span><span>())</span>
<span># Python3 program to demonstrate the use # of isdecimal() </span>
<span># vaid decimal </span><span>s</span> <span>=</span> <span>'12345'</span>
<span>print</span><span>(</span><span>s</span><span>.</span><span>isdecimal</span><span>())</span>

<span># in case of digit #s = '²123' </span><span>s</span> <span>=</span> <span>'</span><span>\u00B2</span><span>123'</span>
<span>print</span><span>(</span><span>s</span><span>.</span><span>isdecimal</span><span>())</span>

<span># incase of numeric # s = '½' </span><span>s</span> <span>=</span> <span>'</span><span>\u00BD</span><span>'</span>
<span>print</span><span>(</span><span>s</span><span>.</span><span>isdecimal</span><span>())</span>

# Python3 program to demonstrate the use # of isdecimal() 
# vaid decimal s = '12345'
print(s.isdecimal())

# in case of digit #s = '²123' s = '\u00B2123'
print(s.isdecimal())

# incase of numeric # s = '½' s = '\u00BD'
print(s.isdecimal())

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Output

<span>True</span>
<span>False</span>
<span>False</span>
<span>True</span>
<span>False</span>
<span>False</span>
True
False
False

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原文链接：Python String isdecimal()