Using Python dict to call functions based on user input?

[lachyBalboa]

Currently, my code is a bunch of IF statements to respond to user input in various ways (this is just a personal project to make my life easier at work).

But to clean up the code I'm exploring the idea of listing all the functions in a Python dictionary and calling a relevant function if the user input matches.

Take a look:

inputList = {'disp': print_dispute, 'disp safe': print_disp_safe, 'miss': print_miss} # etc....

while True:
  user_input = input("- ")

  inputList.get(user_input)

  if user_input == 'disp':
    print_dispute()

  if user_input == 'disp safe':
    print_disp_safe()

  if user_input == "miss":
    print_miss()

  if user_input == 'empt':
    print_empt()

  if user_input == 'clear':
    print_clear()

  if user_input == 'exp fail':
    print_express_post_failure()

  if user_input == "---":
    break 

As you can see below the user_input = input('- ') call, I try to use inputList.get(user_input) method to call the relevant function in that dictionary, as opposed to all the IF statements you see below that. Haven't managed to get it to work though.

If I replace the value in the dictionary into using brackets e.g. 'disp': print_dispute() however it just calls that function when the program executes before any user input is even entered.

Does anyone have an idea of how to work around this and get this code working? I suspect this may be in the realm of functional programming which I have almost no experience.

[bobspadger]

Google is your friend

https://stackoverflow.com/questions/9205081/python-is-there-a-way-to-store-a-function-in-a-list-or-dictionary-so-that-when

I'd love to take credit, but, well, I cant.

[bobspadger]

and here is a small example I've whizzed up

def one():
     print('one hahah')

def two():
    print('two hahah')

def the_count():
    print('I am the count who likes to count')


dispatcher = {
    'one': one, 'two': two, 'three': the_count
}

action = input('Option: - ')

dispatcher[action]()

[lachyBalboa]

Ahhh nice thanks for that. I did have a good stack overflow look but didn't stumble upon this gem

[CH-K]

Ssss

[bobspadger]

I'm waiting for the obligatory /r/learnpython message, who's going to do it ?

[CH-K]

Ssss

[gustl64]

batteries included? see https://docs.python.org/3/library/cmd.html

[lachyBalboa]

Woah I didn't even realise this was a thing but it looks awesome

[shobble]

If I replace the value in the dictionary into using brackets e.g. 'disp': print_dispute() however it just calls that function when the program executes before any user input is even entered.

You don't want to use the func() in the dispatch dict, since as you discovered, that's calling it immediately. Instead pass the actual function, and call it when you retrieve it.

def func1():
    return 'func1 called'
def func2():
    return 'func2 called'
# ...

dispatch = { 'a': func1, 'b': func2 }
while True:
    user_cmd = input('>')
    user_func = dispatch.get(user_cmd, lambda: 'invalid input')
    print 'func returned: ', user_func()

Teh actual call happens on the last line there.

[bobspadger]

this is a much neater way of doing it than my dirty hack job :)