My son (Now 13 years old.) is merrily programming away in Python 3 (Of
course!) and has many projects he is working on. Today he resumed
work on his efforts to create a natural language parser, which he
hopes will enable people to type in commands to a DnD-like game using
natural English. An ambitious project to be sure! He asked me if
there was any way that if he identified a word in the user's input
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. After fumbling around a bit I came up with the
following program for him to play around with:
==========================================================================
#!/usr/bin/env python3
def spam(phrase):
print('spam function said: ', phrase)
def ham(phrase):
print('ham function said: ', phrase)
def eggs(phrase):
print('eggs function said: ', phrase)
def get_input():
function = input('Which do you want: spam, ham or eggs?\n')
phrase = input('\nHow do you want your food to be prepared?\n')
return function, phrase
def check_fcn_input(function):
valid_fcns = ['spam', 'ham', 'eggs']
if function in valid_fcns:
return True
else:
return False
def run_fcn(function, phrase):
fcn_dict = {'spam': spam, 'ham': ham, 'eggs': eggs}
fcn_dict[function](phrase)
def main():
function, phrase = get_input()
while not check_fcn_input(function):
print("You made an invalid food choice! Let's try this again!")
function, phrase = get_input()
run_fcn(function, phrase)
if __name__ == '__main__':
main()
==========================================================================
This works, but I cannot but help wondering if there is a more direct
approach? Given the above three functions spam(), ham() and eggs(),
and given a string 'ham', what is the quickest, most direct way to run
that function? Or similarly for the other two?
Oh, and I suppose I should ask for a critique of the code as written
for appropriate Python style, proper targeted function use, etc. I am
always eager to learn! However, I did not use doc strings for the
functions or write tests. If I were actually planning on using this
for real, I would have done so.
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. These contain
essentially the same information. Would this be a case for a global
function dictionary (Which I could also use to check for valid
functions.) or perhaps a class which only exists to have this function
dictionary?
TIA!
--
boB
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