code: def parse(self, lines):
      
  
      if isinstance(lines, str):
        lines = lines.split('\n')
      sub = _re.sub
      for line in lines:
        if line.endswith('\n'):
          line = line[:-1]
        line = line.lstrip()
        if not line.startswith('#'):
          invert = False
          if line.startswith('!'):
            line = line[1:]
            invert = True
          while line.endswith(' ') and line[-2:] != '\ ':
            line = line[:-1]
          line = sub(r'\\([!# ])', r'\1', line)
          if '/' in line and not line.startswith('/'):
            # Patterns with a slash can only be matched absolute.
            line = '/' + line
          self.patterns.append(Pattern(line, invert))
docs: Parses the `.gitignore` file represented by the *lines*.