How to receive input parameters in various python scripts through a common json file

Question

I have the following json input parameters file

#input.json
{
        "nx": 401, 
        "ny": 401,
        "T" : 10,
        "nt" : 20,
        "D" : 0.2,
        "Sgma": 0.243,
        "M": 0.0052
}

that is passed onto different python scripts, for eg.

#test1.py
import numpy,os

def simple(nx,ny,D,Sgma, M, T,nt):  #parameters as function arguments
    k = Sgma + 0.02
    print("this is domain size", ny)
    print("this is dif time", T)
    print("this is K param", k)

#test2.py
import numpy,os

def simple_n(nx,ny,D,Sgma,M,T,nt):  #parameters as function arguments
    k = M + 0.02
    print("this is domain size", ny)
    print("this is sim time", D)
    print("this is K param", k)

I execute both the above python scripts through a main.py that passes the input parameters with argparse.

As you can see, only some, not all of the parameters are required in individual scripts. My question: Is there a way to pass only the required arguments in simple() ?

For example: def simple(ny,T,k) for test1.py and def simple(ny,D,k) for test2.py rather than def simple(nx,ny,D,Sgma, M,T,nt). Since I will be dealing with large sets of parameters as initial config, I would like to know an efficient way to pass the initial parameters in different python codes as function arguments. Thanks

Asked By: newstudent

||

Source

Answer 1

You can use **kwargs for that. It is a pattern often used in python where you pass named parameters to a function and inside the function you access the values you need.

def simple(**kwargs):
    ny = kwargs.get('ny', None)

    if ny is None:
        print("Parameter 'ny' is required.")

# Call the function with only required arguments
simple(ny=1, D=15, nt=2)

Or you could add default values to your function and pass values by their name.

def simple(nx=0, ny=0, D=0, Sgma=0, M=0, T=0, nt=0):
    pass

# Call the function with only required arguments
simple(ny=1, D=15, nt=2)

UPDATE

a = {"foo": "bar", "baz": 1}
def simple(foo=None, bar=None, baz=None):
    print(foo)
    print(bar)
    print(baz)

>>> simple(**a)
bar
None
1

Answered By: finngu

How to receive input parameters in various python scripts through a common json file

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