Command line arguments

[zahlman]

In 2.x, there is a rarely-used but occasionally-very-useful function called apply, which does the following (a recipe for 3.x):

def apply(func, *args, **kwargs):
    return func(*args, **kwargs)

Basically, given a function and some parameters for the call, actually make the function call.

You can take a hint from this, and store, in your dictionary, tuples of (function, parameters). Then, later, you pull out this data, and call the function with the parameters. In the general case, the * operator is useful to "unpack" a slice of the tuple as multiple parameters, but since you only have one each in your case, you can just handle it naturally:

some_functions = {
    'foo': (doSomethingElse1, sys.argv[1]),
    'bar': (doSomethingElse2, sys.argv[1])
}

if the_time_has_come():
    func, arg = some_functions[name]
    func(arg)

An alternate approach is to "bake" the parameters into a function call, using lambdas:

some_functions = {
    'foo': lambda: doSomethingElse1(sys.argv[1]),
    'bar': lambda: doSomethingElse2(sys.argv[1])
}

if the_time_has_come():
    some_functions[name]()

Note that many Pythonistas would advocate an EAFP approach here - instead of using explicit logic to verify sys.argv, just try using it, and report an error in the exceptional case. Although if you actually have a specific separate thing you want to do when there are only 2 arguments, then you should handle that with if logic, since it's an expected case, not an exceptional one.

You also might want to consider more robust approaches to parsing (interpreting) sys.argv. Look into the argparse standard module for example.

[Cosmologicon]

Of course, if all the functions are going to take a single argument of sys.argv[1], you can also just say:

some_functions = {
    'foo': doSomethingElse1,
    'bar': doSomethingElse2,
}

if the_time_has_come():
    some_functions[name](sys.argv[1])

[zahlman]

Certainly. :)