Feed python function with a variable number of arguments

Question

I have a script that reads a variable number of fields from an input file and pass them to a function as arguments. For example:

file 1 with fields: A,B a

Answer 1

Read the fields (arguments) into a list and then use argument unpacking:

function(*fields)

Below is a demonstration:

>>> def func(*args):
...     return args
...
>>> fields = ["A", "B", "C"]
>>> func(*fields)
('A', 'B', 'C')
>>> fields = ["A", "B", "C", "D"]
>>> func(*fields)
('A', 'B', 'C', 'D')
>>>

Answer 2

you should use args and kwargs like this:

def foo(*args, **kwargs):
  pass

in this way you can get positional and named parameters, args should be a list of values, holding the positional arguments, kwargs should be a dictionary, its keys the argument name with its value