On 17/05/17 03:49, boB Stepp wrote:
> corresponding to one of his functions or methods, if he could use that
> word to run a function of the same name. I said I had done something
> once where I used the word as a dictionary key, which was then used to
> call the function.
That's the usual approach.
> def check_fcn_input(function):
> valid_fcns = ['spam', 'ham', 'eggs']
> if function in valid_fcns:
> return True
> else:
> return False
I would rewrite this to return the function or None
def get_input_function(name):
return functions.get(name)
You can then use the result as a boolean in a
test or simply call it directly using Pythons
"ask forgiveness" approach:
name,phrase = get_input()
try: get_input_function(name)(phrase)
except TypeError: pass
> This works, but I cannot but help wondering if there is a more direct
> approach?
Not really. Remember that Python itself uses a dictionary
to translate names to function calls. If its good enough
for the interpreter its probably good enough for you! :-)
> Hmm. It bothers me that in check_fcn_input() I have a list valid_fcns
> and in run_fcn() I have a dictionary fcn_dict.
A global dict wins here.
You could of course make it a class but I'm not sure that
actually makes anything clearer in this case.
HTH
--
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.amazon.com/author/alan_gauld
Follow my photo-blog on Flickr at:
http://www.flickr.com/photos/alangauldphotos
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