Explanation of regexp multiple lookahead behavior

Please help understand why r'\b\w+(?=\d)(?=[A-Z])' does not match Python3A.

It says r'\b\w+(?=\d)(?=[A-Z])' search for words followed by a digit and then by a capital letter. Python3A consists of a word Python followed by a digit 3 and a capital letter A. If the statement is correct, then it should match Python.

Multiple Positive Lookaheads
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>Solution :

It doesn’t match because you have two lookaheads in the same place, one of which asserts a number, and the other asserts a capital letter. Since there is no overlap between those, one of them can’t be true and so the match fails. What you need is just a single lookahead for a digit followed by a capital letter:


Regex demo on regex101

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