Am 10.04.2011 18:21, schrieb Mel:
Chris Angelico wrote:
Who would use keyword arguments with a function that takes only one arg
anyway?
It's hard to imagine. Maybe somebody trying to generalize function calls
(trying to interpret some other language using a python program?)
# e.g. input winds up having the effect of ..
function = bool
name = 'x'
value = 'the well at the end of the world'
## ...
actions.append ((function, {name:value}))
## ...
for function, args in actions:
results.append (function (**args))
Wrong structure.
Better do
function = bool
value = 'the well at the end of the world'
## ...
actions.append((function, (value,), {}))
## ...
for function, args, kwargs in actions:
results.append(function(*args, **kwargs))
or maybe even better (taking care for closures):
function = bool
value = 'the well at the end of the world'
## ...
actions.append(lambda val=value: function(val))
## ...
for function in actions:
results.append(function())
Not something I, for one, do every day. But regularity in a language is
good when you can get it, especially for abstract things like that.
I can sort of guess that `dir` was perhaps coded in C for speed and doesn't
spend time looking for complicated argument lists.
Python is a pragmatic language, so all the rules come pre-broken.
Mel.
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