Can I dynamically pass a list of arguments to a python function with predefined arguments? [duplicate]

Question

I have a python function bar(a=None, b=None, c=None, d=None, e=None). I was wondering if it was possible to build the list of arguments I want to pass in, with a list or a string, or something.

I would have a list of attributes to look for and ideally I would simply loop over them and build the argument string.

For example, something like:

dict = {'a' : 5, 'c' : 3, 'd' :9} 
arg_string = ""
for k, v in dict.iteritems():
    arg_string += "{0}={1},".format(k, v)

bar(arg_string)

In this case I don't have any values to pass in for b and e, but the next time the program runs there may be.

Is this possible?

I know the string being built in the for loop will probably be invalid because of the comma at the end. But i didn't think it was necessary to write the handling for that

Answer 1

The good news is that you don't even need a string. . .

mapping = {'a': 5, 'c': 3, 'd': 9} 
bar(**mapping)

should work. See the Unpacking Argument Lists (and surrounding material) in the official python tutorial.