Recent python versions complain when backslashes in strings create invalid
escape sequences. This causes issues for strings used as regex patterns like
`'^List\[(.*)\]$'` where you want the regex parser to treat `[` and `]`
as literals. Double-backslashing is one way to fix it but simply converting
the string to a raw string `re.match(r'^List\[(.*)\]$', text)` is easier
and less error prone.
(cherry picked from commit
f80e2405e64c32898380230c5f5bf38c168814e5)
@param type_string: Type string to parse
@returns Type parameter of the list, or None if not a List.
"""
- list_match = re.match('^List\[(.*)\]$', type_string)
+ list_match = re.match(r'^List\[(.*)\]$', type_string)
return list_match and list_match.group(1)