[Tutor] Help with Python Regular Expressions

[Greg Chapman]

>def makeIfDefName(fileName):
>     import re
>     p = re.compile('([A-Z])')
>     newFileName = p.sub(r'_\1', fileName)
>     return newFileName.upper()
>
>When given "FooBar" this returns "_FOO_BAR".  I could do it without
regular
>expressions, I suppose, but I'd like to learn RE's too.

Try your regular expression like this: p = re.compile(r'\B([A-Z])')

The '\B' specifies that the match not occur on a word boundary, ie at
the beginning of the word.  This works for me, although I've only
subjected it to limited testing.

HTH,
greg