[Python-Dev] PEP 8: Discourage named lambdas?

[Michael Foord]

Terry Reedy wrote:
> Some people write
>     somename = lambda args: expression
> instead of the more obvious (to most people) and, dare I say, standard
>     def somename(args): return expression
>   

Visually I find the second form very ugly.

The colon indicates to me that a new line is expected, and breaking that 
expectation breaks my flow of code reading.

I very *rarely* use lambdas in the form you show, but where you do I 
prefer them to the single line function.

Michael Foord


> The difference in the result (the only one I know of) is that the code and 
> function objects get the generic name '<lambda>' instead of the more 
> informative (in repr() output or tracebacks) 'somename'.  I consider this a 
> disadvantage.
>
> In the absence of any compensating advantages (other than the trivial 
> saving of 3 chars), I consider the def form to be the proper Python style 
> to the point I think it should be at least recommended for the stdlib in 
> the Programming Recommendations section of PEP 8.
>
> There are currently uses of named lambdas at least in urllib2.  This to me 
> is a bad example for new Python programmers.
>
> What do our style mavens think?
>
> Terry Jan Reedy
>
>
>
>
>
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