How to concatenate several logical operators like 'a and not (b or c or d)'

Question

How do I write this correctly:

for root, dirs, files in os.walk(SEARCHDIR):
    files = [f for f in files if not f[0] == '.' and not ("BLACKBOX" or ".RTN" or ".log") in f]

I want to achieve my file list to contain all files instead of hidden files or files conaining one of the strings "BLACKBOX" or ".RTN" or ".log". Anyway only the first expression is evaluated ("BLACKBOX") the others are ignored.

i suggest a cleaner option, separating your construction of that list into several lines. much easier to read — Jack Hamby, May 28 '19 at 16:10
You need to chain the *comparisons*, not the items you are comparing to. — chepner, May 28 '19 at 16:22

score 1 · Accepted Answer · answered May 28 '19 at 16:16

1

You can combine both the not commands to one as

for root, dirs, files in os.walk(SEARCHDIR):
    files = [f for f in files if not (f[0] == '.' and any(i in f for i in ["BLACKBOX", ".RTN", ".log"]))]

answered May 28 '19 at 16:16

Sheldore

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'any' was the key – Stefatronik Aug 26 '19 at 09:54

score 0 · Answer 2 · answered May 28 '19 at 16:11

0

Change this:

not ("BLACKBOX" or ".RTN" or ".log") in f

To this:

not any([x in f for x in ["BLACKBOX", ".RTN", ".log"]])

answered May 28 '19 at 16:11

goodvibration

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score 0 · Answer 3 · answered May 28 '19 at 16:17

You should try something like this:

filterFn = lambda f: f[0] == '.' or any(s in f for s in ['BLACKBOX','.RTN','.log'])
files = [f for f in files if not filterFn(f)]

My local test shows:

>>> files = [f for f in ('.', 'TEST', 'test.RTN') if not filterFn(f)]
>>> files
['TEST']

How to concatenate several logical operators like 'a and not (b or c or d)'

3 Answers3