Since this regex has gotten pretty dense, could you write it out in `re.VERBOSE` mode, and use keyword identifiers for the capturing groups?  Something like:
```
re.compile(r'^ \s* # \s* '
          r'(?P<colnumber> [0-9]+) \s+ '  
          r'(?P<colname> \w+) \s* ' 
          etc, re.VERBOSE)
```