Python String isalpha()

Summary: in this tutorial, you’ll learn how to use the Python string isalpha() method to check if all characters in a string are alphabetic.

Introduction to the Python string isalpha() method

The string isalpha() method returns True if:

  • the string contains only alphabetic characters
  • and the string has at least one character.

Otherwise, the isalpha() method returns False.

The following shows the syntax of the isalpha() method:

str.isalpha()Code language: CSS (css)

Note that alphabetic characters are characters defined as letters in the Unicode character database.

Python string isalpha() method examples

The following example uses the isalpha() method to check if a string contains alphabetic characters:

name = 'John'
print(name.isalpha())Code language: PHP (php)

Output:

TrueCode language: PHP (php)

It returned True because the string 'John' contains only alphabetic characters.

The following example returns False because the string 'Jane Doe' contains a space:

name = 'Jane Doe'
print(name.isalpha())Code language: PHP (php)

Output:

FalseCode language: PHP (php)

In general, if the string contains whitespace, the isalpha() method returns False.

The following example uses the isalpha() method to check if all the characters in the string 'Python3' are alphabetic. It returns False because the string contains a number:

s = 'Python3'
print(s.isalpha())Code language: PHP (php)

Output:

FalseCode language: PHP (php)

The following example returns False becuase the string is empty:

empty = ''
print(empty.isalpha())Code language: PHP (php)

Output:

FalseCode language: PHP (php)

Summary

  • Use the Python string isalpha() method to check if all characters in a string are alphabetic.
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