Python String isdecimal() Method

This is a tutorial of the Python String isdecimal() method. Learn to check if a given string only contains decimal characters or not with examples.

Python String isdecimal()

The str.isdecimal() method returns True if the given string contains only decimal characters (0-9) and if not it returns False.

Syntax

Given below is the syntax of the str.isdecimal() method.

isdecimal() Parameters

This method does not take any arguments as it only checks the characters in the string on which it is applied, so no additional data is required in the form of arguments.

isdecimal() Return Value

It returns the boolean value True or False according to the following logic.

• Returns True if all of the characters in the given string are only decimals.
• Returns False if not all the characters in the given string are decimals.

Examples

Given below are the two examples demonstrating the usage of the Python String isdecimal() method.

Example 1. Checking a given String contains all the decimals or not using str.isdecimal() method

In this example, we’re applying the method isdecimal() on several different strings to check the result, for what strings it returns True and for what it returns False.

#String with only decimals
line = "1234567890"
print(line.isdecimal())

#String with decimals and a whitespace
line = "12345 67890"
print(line.isdecimal())

#String with decimals and special symbols
line = "12345?"
print(line.isdecimal())

#String with Alphanumeric Characters
line = "Hello12345"
print(line.isdecimal())

#String with only Alphabets
line = "Abcd"
print(line.isdecimal())

#String with Powers
line = '12\u00B2'
#represents '12^2'
print(line.isdecimal())

#String with Special Fractions
line = "½"
print(line.isdecimal())

Output.

True
False
False
False
False
False
False

Example 2. Using the Python String isdecimal() method with if-else statement

In the following example, we’ve directly used the str.isdecimal() method as the condition for the if-else statement to print a string accordingly after checking if the given string only contains decimals or not.

#Using str.isdecimal() with if-else statement

#Given String
name = "HelloWorld12345"

if name.isdecimal():
    print("name only contains decimals.")
else:
    print("name also contains characters other than decimals.")

Output.

name also contains characters other than decimals.

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