Compare strings in python like the sql “like” (with “%” and “_”)

Question

I have a list in python with some strings, and I need to know witch item in the list is like "A1_8301". This "_" means that can be any char. Is there a quick way to do that?

If I was using SQL, i just type something like "where x like "A1_8301"

Thank you!

Answer 1

In Python you'd use a regular expression:

import re

pattern = re.compile(r'^A1.8301$')
matches = [x for x in yourlist if pattern.match(x)]

This produces a list of elements that match your requirements.

• The ^ and $ anchors are needed to prevent substring matches; BA1k8301-42 should not match, for example. The re.match() call will only match at the start of the tested string, but using ^ makes this a little more explicit and mirrors the $ for the end-of-string anchor nicely.
• The _ in a SQL like is translated to . , meaning match one character .

Answer 2

regular expressions are probably the way to go. IIRC, % should map to .* and _ should map to . .

matcher = re.compile('^A1.8301$')
list_of_string = [s for s in stringlist if matcher.match(s)]