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()
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())
Output:
True
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())
Output:
False
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())
Output:
False
The following example returns False becuase the string is empty:
empty = ''
print(empty.isalpha())
Output:
False
Summary
- Use the Python string
isalpha()method to check if all characters in a string are alphabetic.