IllegalCharacterError when processing some workbooks

Created originally on Bitbucket by private (Alex Stapleton)

(I know very little about OO-XML so this is mostly guess work, sorry.)

Some of our workbooks raise IllegalCharacterError when load_workbook()ing under 1.9. This appears to be because they contain string values that start with a space and the ILLEGAL_CHARACTERS_RE pattern is both incorrect and that it is used with match instead of search.

In 1.9 we have

ILLEGAL_CHARACTERS_RE = re.compile('|'.join(chr(x) for x in range(33)))

i.e. the pattern is 0x00|0x01|...|0x20.

I suspect this pattern is wrong because 0x20 is space. It seems unlikely that strings should never contain spaces. I suggest [\000-\037] as a replacement.

Secondly this problem only appears on strings that start with things that match this pattern because the pattern is checked like this

if ILLEGAL_CHARACTERS_RE.match(value):

and the Python docs say this about match

If zero or more characters at the beginning of string match the regular expression pattern, return a corresponding MatchObject instance.

It seems likely the behaviour that was intended is that of search.

Scan through string looking for a location where the regular expression pattern produces a match, and return a corresponding MatchObject instance.

Or perhaps next(re.finditer, None) since only care if there are greater than zero matches?

Attachments: space-example.xlsx