re 模块

match

import re
example = "Hello World, I am 24 years old."
pattern = re.compile(r"(\S+) (\S+) (\S*) (\S+) (\d+) (\S+) (\S+)")
m = pattern.match(example)
print m.group(0)    # Hello World, I am 24 years old.
print m.group(1)    # Hello
print m.group(2)    # World

or

m = re.match(r'(\S+) (\S+) (\S*) (\S+) (\d+) (\S+) (\S+)', example)
print m.group()

findall

import re
example = "Hello World, I am 24 years old."
pattern = re.compile(r"\d+")
m = pattern.findall(example)
print m # ['24']

sub

import re
example = "Hello World, I am 24 years old."
m = re.sub(r"\d+", "48", example)
print m

or

import re
example = "Hello World, I am 24 years old."
m = re.sub(r"(\d+)", lambda x: "[" + x.group(1) + "]", example)
print m # Hello World, I am [24] years old.

or

def my_replace(match):
    return "[" + match.group(1) + "]"
m = re.sub(r"(\d+)", my_replace, example)