Python - How to pass all args values in method for unit test?

Question

I'm stuck in a situation.

Below is the illustration of same.

I'm passing the values through argument parse. Values of a, b , c.

Code is -

initial_foo(args): **codes** args.a, args.b are used here.

If I print args, it returns self.args = argsparse.Namespace(a='hii',b='bye',c='yolo'). Now if I pass args in initial_foo(self.args) it automatically picks up the values provided through args.

Now, I want to test this initial_foo(args) method. So, probably I can do is that setting up the same self.args = argsparse.Namespace(a='hii',b='bye',c='yolo') and passing in initial_foo method. What if I don't want to use this.

Is there any other solution of the same ?

Anything which we can do through ```**locals() ?

Please let me know if you have any doubts.

• BlackVegetable: I'm having trouble understanding what you're trying to do. You are trying to pass in variables to your function, right? But you don't want to bundle them in the self.args object? The use of argsparse implies you are getting these arguments from the command line, right? So why not call inital_foo via inital_foo('hii', 'bye', 'yolo')?
• PySaad: @BlackVegetable I've passed 3 arguments through command line but initial_foo(args) is only using 2 arguments. So, if I pass args it automatically reads the value of args of the given args.a and args.b . Thing is this is just an example. In my code, I'm passing 10 args and foo_method is using 5 arguments. But my main question is for testing pupose. How to perform that. I know you will help me .thanks!
• BlackVegetable: As a matter of best practice, you should probably pass the arguments as individual arguments and not as a bundled object to be consumed by each function. It will be less error prone to do: inital_foo(args.a, args.b). Most of the time if you have over, say, 7 arguments to a function, that is a good clue you should refactor to make your functions smaller and require less data passing. I'm not sure I can help you without a real code sample here.

Answer 1

If you are thinking on how to unittest the initial_foo without creating an argparse.Namespace object, then you could pass initial_foo any object which with properties 'a', 'b', 'c' and allows dot notation call.

locals() doesn't work because that gives you a dict. dictionary elements are accessed through index (__getitem__), not dot operator (__getattr__)

You could create a class, with these props and pass in an object of that class.

class Data(object):
 def __init__(self, a, b, c):
 self.a = a
 self.b = b
 self.c = c
initial_foo(Data(1,2,3))

Or pass in a named tuple

from collections import namedtuple
data = namedtuple('data', ['a', 'b', 'c'])
initial_foo(data(1,2,3))

Anything similar should work too.

• PySaad: Perfecto!! Thanks.