python正则表达式re模块详解

快速入门

    import re

    pattern = 'this'
    text = 'Does this text match the pattern?'

    match = re.search(pattern, text)

    s = match.start()
    e = match.end()

    print('Found "{0}"\nin "{1}"'.format(match.re.pattern, match.string))
    print('from {0} to {1} ("{2}")'.format( s, e, text[s:e]))

执行结果：

    #python re_simple_match.py 
    Found "this"
    in "Does this text match the pattern?"
    from 5 to 9 ("this")
    import re

    # Precompile the patterns
    regexes = [ re.compile(p) for p in ('this', 'that')]
    text = 'Does this text match the pattern?'

    print('Text: {0}\n'.format(text))

    for regex in regexes:
      if regex.search(text):
        result = 'match!'
      else:
        result = 'no match!'

      print('Seeking "{0}" -> {1}'.format(regex.pattern, result))

执行结果：

    #python re_simple_compiled.py 
    Text: Does this text match the pattern?

    Seeking "this" -> match!
    Seeking "that" -> no match!

    import re

    text = 'abbaaabbbbaaaaa'

    pattern = 'ab'

    for match in re.findall(pattern, text):
      print('Found "{0}"'.format(match))

执行结果：

    #python re_findall.py 
    Found "ab"
    Found "ab"

    import re

    text = 'abbaaabbbbaaaaa'

    pattern = 'ab'

    for match in re.finditer(pattern, text):
      s = match.start()
      e = match.end()
      print('Found "{0}" at {1}:{2}'.format(text[s:e], s, e))

执行结果：

    #python re_finditer.py 
    Found "ab" at 0:2
    Found "ab" at 5:7