Python3 isalpha() Method

Python3 字符串Python3 Strings

Description

The Python isalpha() method checks whether a string consists only of letters or characters.

  • Empty string: If the string is empty (length 0), it returnsFalse, because an empty string contains no letters.
  • Case sensitivity：isalpha()The method is case-sensitive, meaning only alphabetic characters are considered valid.
  • Special characters: Special characters (such as punctuation, spaces, digits, special symbols, etc.) are not considered letters.

Syntax

isalpha() method syntax:

str.isalpha()

Parameters

  • None.

Return Value

Returns True if the string has at least one character and all characters are letters or characters, otherwise returns False.

Example

The following example demonstrates the isalpha() method:

Example

#!/usr/bin/python3

str = "example"
print (str.isalpha())

# Letters and Chinese characters
str = "example Rookie Tutorial"
print (str.isalpha())

str = "Example example....wow!!!"
print (str.isalpha())

The output of the above example is:

True
True
False

More examples:

Example

# Example 1: String containing only letters
print("HelloWorld".isalpha())  # Output: True

# Example 2: String containing digits
print("Hello123".isalpha())  # Output: False

# Example 3: String containing spaces
print("Hello World".isalpha())  # Output: False

# Example 4: String containing special characters
print("Hello#World".isalpha())  # Output: False

# Example 5: Empty string
print("".isalpha())  # Output: False

# Example 6: String containing underscores
print("Hello_World".isalpha())  # Output: False

# Example 7: String containing non-ASCII letters
print("HélloWorld".isalpha())  # Output: True, because é is a letter

Python3 字符串Python3 Strings

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