1  import re
       2  
       3  
       4  def translate(pattern):
       5      r"""
       6      Given a glob pattern, produce a regex that matches it.
       7  
       8      >>> translate('*.txt')
       9      '[^/]*\\.txt'
      10      >>> translate('a?txt')
      11      'a.txt'
      12      >>> translate('**/*')
      13      '.*/[^/]*'
      14      """
      15      return ''.join(map(replace, separate(pattern)))
      16  
      17  
      18  def separate(pattern):
      19      """
      20      Separate out character sets to avoid translating their contents.
      21  
      22      >>> [m.group(0) for m in separate('*.txt')]
      23      ['*.txt']
      24      >>> [m.group(0) for m in separate('a[?]txt')]
      25      ['a', '[?]', 'txt']
      26      """
      27      return re.finditer(r'([^\[]+)|(?P<set>[\[].*?[\]])|([\[][^\]]*$)', pattern)
      28  
      29  
      30  def replace(match):
      31      """
      32      Perform the replacements for a match from :func:`separate`.
      33      """
      34  
      35      return match.group('set') or (
      36          re.escape(match.group(0))
      37          .replace('\\*\\*', r'.*')
      38          .replace('\\*', r'[^/]*')
      39          .replace('\\?', r'.')
      40      )