string模塊提供了許多字符串常量，如下所示：

__all__ = ["ascii_letters", "ascii_lowercase", "ascii_uppercase", "capwords",
           "digits", "hexdigits", "octdigits", "printable", "punctuation",
           "whitespace", "Formatter", "Template"]

# Some strings for ctype-style character classification
whitespace = ‘ \t\n\r\v\f‘
ascii_lowercase = ‘abcdefghijklmnopqrstuvwxyz‘
ascii_uppercase = ‘ABCDEFGHIJKLMNOPQRSTUVWXYZ‘
ascii_letters = ascii_lowercase + ascii_uppercase
digits = ‘0123456789‘
hexdigits = digits + ‘abcdef‘ + ‘ABCDEF‘
octdigits = ‘01234567‘
punctuation = r"""!"#$%&‘()*+,-./:;<=>?@[\]^_`{|}~"""
printable = digits + ascii_letters + punctuation + whitespace　

這些常量在很多場合很有用處，比如要去掉字符串左邊的所有字母：

>>> import string
>>> a = "asdfjsdnfnfjirrjwoe12345dsf6sdfjksdfj"
>>> a.lstrip(string.ascii_letters)
‘12345dsf6sdfjksdfj‘
>>> 

提供了一個函數capwords，函數原型為：

def capwords(s, sep=None):
    return (sep or ‘ ‘).join(x.capitalize() for x in s.split(sep))

還有兩個類：Template和Formatter，後續研究。

Python 模塊學習：string模塊1