lambdak: multi-line lambda implementation in native Python

Steven D'Aprano steve+comp.lang.python at pearwood.info
Thu Jan 15 15:29:22 CET 2015


Ian Kelly wrote:

> On Wed, Jan 14, 2015 at 11:06 PM, Steven D'Aprano <steve at pearwood.info>
> wrote:
>> I have a function, which I put into an expression like this:
>>
>> def func(a, b=None):
>>     global spam
>>     import math
>>     spam = [a, b]*3
>>     print spam
>>     del spam
>>
>>
>> value = [1, "hello", int, func]
>> del func
>>
>> How would I use lambdak to write that as an expression
>>
>> value = [1, "hello", int, ??????? ]
>>
>> without the intermediate def?
> 
> 
> # Untested, but seems like this should work.
> 
> value = [1, "hello", int, given_(lambda a, b=None:
>     import_("math", lambda math:
>     import_("operator", lambda operator:
>     do_(lambda: operator.setitem(globals(), 'spam', [a, b]*3), lambda:
>     print_(globals()['spam'], lambda:
>     do_(lambda: operator.delitem(globals(), 'spam')))))))]

Thank you for showing me that.

Now I shall try very hard to forget I ever saw it. 

*shudders at the thought of maintaining such a beast*



-- 
Steven




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