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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def match_main(self, text, pattern, loc):
 """Locate the best instance of 'pattern' in 'text' near 'loc'. Args: text: The text to search. pattern: The pattern to search for. loc: The location to search around. Returns: Best match index or -1. """

    # Check for null inputs.
    if text == None or pattern == None:
      raise ValueError("Null inputs. (match_main)")

    loc = max(0, min(loc, len(text)))
    if text == pattern:
      # Shortcut (potentially not guaranteed by the algorithm)
      return 0
    elif not text:
      # Nothing to match.
      return -1
    elif text[loc:loc + len(pattern)] == pattern:
      # Perfect match at the perfect spot!  (Includes case of null pattern)
      return loc
    else:
      # Do a fuzzy compare.
      match = self.match_bitap(text, pattern, loc)
      return match