If a string as a dot (.) surrounded by double-quotes, then it's valid. Dot on it's own or a single double-quote are invalid.
# Valid str examples
str1 = 'Don "B." White'
str10 = 'Don "M.dom" White'
str2 = 'Don "B." White "H." Joe'
# In-valid str examples
str3 = 'Don "B. White'
str4 = 'Don "B." White "H Simpson'
str5 = 'Don B. White' # dot must have double quotes around it e.g. "B."
I can check that a dot is surrounded by double quotes using
re.search(r'(?!")\.(?!")', str)
but struggling a bit to construct reg to detect single double in str3 or str4
I tried different variants of negative lookahead r'"(?!")' (i know it's wrong) or [^"] regex but can't seem to get it working. Any ideas?
You may be able to use this regex:
^(?:[^".\n]*"[^"\n.]*\.[^"\n]*")*[^".\n]*$
RegEx Demo:
^: Start(?:: Start non-capture group
[^".\n]*: Match 0 or more of any char that are not " and . and not line break": Match a "[^"\n.]*: Match 0 or more of any char that are not " and . and not line break\.: Match a .[^"\n]*: Match 0 or more of any char that are not " and not line break": Match a ")*: End non-capture group. Repeat this group 0 or more times[^".\n]*: Match 0 or more of any char that are not " and not line break$: End