String functions

Python offers a lot of functions that enable you to modify strings. For example, there are functions to transform all characters in a string to uppercase, obtain the length of a string, strip leading and trailing spaces in a string, etc.

Here is a brief description of some of the commonly used functions:

• capitalize() – capitalizes the first letter of a string.
• isdigit() – returns True if a string contains only digits.
• islower() – returns True if all alphabetic characters are in lowercase.
• len(string) – obtains the length of string.
• lower() – converts all uppercase letters to lowercase.
• upper() – converts all lowercase letters to uppercase.
• strip() – strips all leading and trailing whitespace characters.
• swapcase() – inverts the case of each alphabetic character.

Here are a couple of examples:

 >>> newString='Hello world!'
 >>> len(newString)
 12
 >>> newString.isdigit()
 False
 >>> newString.islower()
 False
 >>> newString.lower()
 'hello world!'
 >>> newString.swapcase()
 'hELLO WORLD!'