How to construct dynamic function invocation with variable arguments in Python

Question

I'm attempting to wrap a call to an operation with a variable argument list into a generalized function with fixed arguments like this:

def vectorizeIt(args, op)

op is a function with a variable number of arguments and args is a list with the arguments I'd like to pass to it. For example if len(args) == 3 then I'd like to call op like this: op(args[0],args[1],args[2]). As far as I can tell, op needs to have the arguments explicitly passed like that; I can't change the argument list to just be a single list or dictionary. Any suggestions about how to do this are appreciated.

Answer 1

Use the "splat" operator * to apply an arbitrary number of arguments to op:

def vectorizeIt(args, op):
    op(*args)

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Reference:

• Salty Crane: How to use *args and **kwargs (also linked aboved)
• Unpacking argument lists (official docs)