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From: Paul Rubin <no.email@nospam.invalid>
Newsgroups: comp.lang.python
Subject: Re: What behavior would you expect?
Date: Thu, 19 Feb 2015 23:18:04 -0800
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Chris Angelico <rosuav@gmail.com> writes:
>>   if len(fs) == 0:  ... # didn't get a filename
> Bikeshedding: That could be written as simply "if not fs". :)

Yeah, in that instance you could do that.  It's an unsafe practice when
None is used as the no-value marker, since the empty string is a
perfectly good string and also converts to boolean false.