Ferdinand Sousa wrote:
Hi
Some weeks back I had been following the thread "Why can't assign to
function call". Today, I saw the "function scope" thread, and decided I
should ask about the behaviour below:
>>>
# Simple variables
>>>p=55
>>> q=p
>>> q
55
>>> q=44
>>> p
55
>>>
>>>
# In a function
>>> def dd(d):
del d['key']
return d
You both mutated and returned the input object. This is undesirable.
All built-in functions and methods that mutate an object have a verb for
a name and return nothing. (Ok, find an exception if you can, but that
is the intented convention.) Statements, of course, also have no
'return'. So either
def strip_key(d):
del d['key']
# or
def stripped_of_key(d):
newd = dict(d)
del newd['key']
return newd
tjr
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