Get The Actual Ending When Testing With .endswith(tuple)

I found a nice question where one can search for multiple endings of a string using: endswith(tuple) Check if string ends with one of the strings from a list My question is, how ca

Solution 1:

>>>s = "ERTYHGFYUUHGFREDFYAAAAAAAAAA">>>endings = ['AAAAA', 'AAAAAA', 'AAAAAAA', 'AAAAAAAA', 'AAAAAAAAA']>>>max([i for i in endings if s.endswith(i)],key=len)
'AAAAAAAAA'

Solution 2:

import re
str= "ERTYHGFYUUHGFREDFYAAAAAAAAAA"
endings = ['AAAAA', 'AAAAAA', 'AAAAAAA', 'AAAAAAAA', 'AAAAAAAAA']

printmax([i for i in endings if re.findall(i+r"$",str)],key=len)

Solution 3:

How about:

len(str) - len(str.rstrip('A'))

Solution 4:

str.endswith(tuple) is (currently) implemented as a simple loop over tuple, repeatedly re- running the match, any similarities between the endings are not taken into account.

In the example case, a regular expression should compile into an automaton that essentially runs in linear time:

regexp = '(' + '|'.join(
   re.escape(ending) for ending insorted(endings, key=len, reverse=True
) + ')$'

Edit 1: As pointed out correctly by Martijn Pieters, Python's re does not return the longest overall match, but for alternates only matches the first matching subexpression:

https://docs.python.org/2/library/re.html#module-re:

When one pattern completely matches, that branch is accepted. This means that once A matches, B will not be tested further, even if it would produce a longer overall match.

(emphasis mine)

Hence, unfortunately the need for sorting by length.

Note that this makes Python's re different from POSIX regular expressions, which match the longest overall match.