[Python-Dev] pep8 reasoning

[Chris Withers]

Hi All,

Apologies if this is considered off topic, but I'm keen to get the 
"language designers" point of view and short of emailing Barry, Guido 
and Nick directly, this seemed like the best place.

I'm having a tough time persuading some people of the benefits of pep8, 
particularly when it comes to applying to an existing large code base.

The biggest sticking point is naming, particularly as it's the one thing 
that can't necessarily be changed module by module. What were the 
compelling reasons to go from mixedCase to underscore_separated? What's 
considered the best approach for migrating from the former to the latter?

A couple of others that have raised some consternation; what are the 
technical reasons for this pattern being bad:

if len(seq)
if not len(seq)

...or, for me, the rather ugly:

if 0 != len(seq)

Likewise, these:

if greeting == True:
if greeting is True:

Please don't misunderstand me: I dislike the above intensely, but it's 
an emotional response based on 10-15 years of doing things the other 
way. I'm interested in arguments that don't include things like "it's 
pythonic" (which some people consider a derogatory term ;-)), or "just 
because", I trust that the stuff in pep8 was done with specific 
reasoning in mind, but I'm feeling rather useless at giving that 
reasoning and I'm hoping you can help :-)

cheers,

Chris