Speed up millions of regex replacements in Python 3

Question

I\'m using Python 3.5.2

I have two lists

• a list of about 750,000 \"sentences\" (long strings)
• a list of about 20,000 \"words\" that I would l

Answer 1

One thing you can try is to compile one single pattern like "\b(word1|word2|word3)\b".

Because re relies on C code to do the actual matching, the savings can be dramatic.

As @pvg pointed out in the comments, it also benefits from single pass matching.

If your words are not regex, Eric's answer is faster.