Python: convert camel case to space delimited using RegEx and taking Acronyms into account

Question

I am trying to convert camel case to space separated values using python. For example:

divLineColor -> div Line Color

This lin

Answer 1

This should work with 'divLineColor', 'simpleBigURL', 'OldHTMLFile' and 'SQLServer'.

label = re.sub(r'((?<=[a-z])[A-Z]|(?

Explanation:

label = re.sub(r"""
        (            # start the group
            # alternative 1
        (?<=[a-z])  # current position is preceded by a lower char
                    # (positive lookbehind: does not consume any char)
        [A-Z]       # an upper char
                    #
        |   # or
            # alternative 2
        (?

If a match is found it is replaced with ' \1', which is a string consisting of a leading blank and the match itself.

Alternative 1 for a match is an upper character, but only if it is preceded by a lower character. We want to translate abYZ to ab YZ and not to ab Y Z.

Alternative 2 for a match is an upper character, but only if it is followed by a lower character and not at the start of the string. We want to translate ABCyz to AB Cyz and not to A B Cyz.