Python args and kwargs: Demystified (Summary)

No hard-coded values ever in my scripts again ! Nice tricks with just one operator. It would be good to explain runtime complexity as well when using such iterables.

Any more practical use-cases for these examples? Just re learning these things again.

Rich, thanks for the video course. I understand what’s going on the args and kwargs. What if you have a simple function like the below. How would implement args to this function.

def get_auth_token(): login = LoginCreds(ip, api, username, password) try: auth = login.LoginToken(ip, api, username, password) return auth except ConnectionError as e: logging.info(“Could not connect to host”) sys.exit(0)

regarding my last post. I have written scripts using the requests module extensively. The responses are large json the jsons are a dictionary of dictionaries. I parse those to get certain information, such as,

permittedInterconnectTypeUri = [‘/rest/interconnect-types/ce3381c9-c948-4c71-946a-8893163ae4a6’] networkUris = [‘/rest/fc-networks/0b20f7fc-370d-4163-b8a6-dc06442f6657’]

These URI need to be placed in a json payload to send to the appliance.

How would i use args and *kwargs in this scenario.

Amazing!

THanks, now I understand these C-like symbols I have seen in argument lists of other code.

I needed an update on this and I have not seen any better! Thanks!

Thanks, very useful..!

Thank you for this tutorial. Very helpful.

I do have a question. On slide 14, you stated:

“5. ** can only be used on dictionaries”

and in the concatenate example, the function says:

def concatenate(**kwargs):

and the function call says:

concatenate(a="Real", b="Python", c="is", d="great!")

The input argument is not a dictionary, rather these are named arguments.

Can you please clarify?

@Danadasa Chan The double star operator (**) has a double meaning in Python, depending on where you use it:

1. You can mark a formal parameter in a function with ** to indicate that any further named parameters will be gathered into a dictionary, typically named kwargs to mean keyword arguments.
2. When calling a function that expects keyword arguments, you can unpack an existing dictionary into key-value pairs.