Best way to save function params for a given URL

Question

I have an endpoint with some required and optional parameters:

Required: ID [str]

Optional: name_1 [str], regex [boolean], ignore_case [boolean]

I want to build a function to use this endpoint:

import requests

def get_function(ID, name_1=None, regex=None, ignore_case=None):

    url= 'heretheurl/{ID}'.format(ID)

    params = {}

    if name_1 is not None:
        params.update({'name_1':name_1})
    if regex is not None:
        params.update({'regex':regex})
    if ignore_case is not None:
        params.update({'ignore_case':ignore_case})

    response = requests.get(url, params=params)

Is it a better way to do this avoiding all these IF s?

Answer 1

You could use **kwargs for the convenience of having the params in a dictionary rather than a bunch of local variables that are then harder to deal with, but then enforce that only certain keyward arguments are acceptable, and for anything else, raise a TypeError . (You could instead have an explicit argument list and then use locals() , but it will include other local variables, so it could get messy.)

import requests

def get_function(ID, **kwargs):

    supported_args = {'name_1', 'regex', 'ignore_case'}
    for key in kwargs:
        if key not in supported_args:
            raise TypeError(f"{key} not supported")

    url = 'heretheurl/{ID}'.format(ID=ID)

    params = dict((k, v) for k, v in kwargs.items() if v is not None)
    
    response = requests.get(url, params=params)


get_function("blah", name_1="stuff", ignore_case=True)

BTW, your format usage is wrong in the line starting url = (you are mixing the usage for keyword and positional parameters), so I've corrected this.

---

The first version of this answer said raise a ValueError if the argument is not supported, but I have changed it to TypeError in order to match what is raised when an unexpected keyword argument is passed while using an explicit argument list.

Answer 2

import requests

def get_function(ID, **kwargs):
    url= 'heretheurl/{ID}'.format(ID)
    response = requests.get(url, params=kwargs)

Answer 3

I guess you could say:

for local, value in locals().items():
    if value is not None:
        params[local] = value