8. Character Classification

It is often helpful to examine a character and test whether it is upper- or lowercase, or whether it is a character or a digit. The string module provides several constants that are useful for these purposes. One of these, string.digits is equivalent to “0123456789”. It can be used to check if a character is a digit using the in operator.

The string string.ascii_lowercase contains all of the ascii letters that the system considers to be lowercase. Similarly, string.ascii_uppercase contains all of the uppercase letters. string.punctuation comprises all the characters considered to be punctuation. Try the following and see what you get.

For more information consult the string module documentaiton (see Global Module Index).