This is basically PEP 505 – None-aware operators ( https://peps.python.org/pep-0505/).
I've generally been opposed to that, but clearly some serious and smart Pythonistas have supported it. That PEP is a bigger lift than your suggestion, but correspondingly more general. On Mon, Jul 10, 2023, 6:04 PM Jothir Adithyan <adithyanjot...@gmail.com> wrote: > Hi everyone, > > I would like to briefly present my idea regarding the `get` function > commonly used with dictionaries. When working with large amounts of JSON > data, I often encounter code that doesn't feel very Pythonic to me. > > Problem Statement: > > The `get` function allows chaining of method calls, which is quite useful > when working with dictionaries. It also has a convenient `default` > parameter that returns a default value if the key is not found in the > dictionary. This feature makes it safe and easy to use. However, problems > arise when the dictionary contains the key we are accessing, but the > corresponding value is `None`. In such cases, subsequent `get` calls fail > because the `get` method belongs to objects of type `dict` and not `None`. > To address this, I propose adding a new parameter to the `get` function or > introducing a new function called `get_or` that swiftly handles this issue. > This new parameter, called `arbitrary`, would accept an arbitrary value to > be returned by subsequent `get` calls in case the retrieved value of the > key is `None`. > > Assumptions: > > The problem statement is based on a few assumptions: > - You prefer chaining `get` statements for cleaner code. > - You expect at least some of the `get` methods to return `None`. > - You want to avoid the hassle of using `try` and `except` for every `get` > chain. > > If you fall into the category of people who wish for a simpler way to work > with dictionaries and handle large amounts of data, I hope you can > empathise with this proposal. > > I have made a simple implementation by modifying the `get` method, which > is below this thread. I would appreciate your valuable input on this > feature. Before diving into coding, I want to make sure this is not a bad > idea waiting to reveal itself in the dark. > > Thank you for taking the time to read this thread. Your feedback is > greatly appreciated. > > Best regards, > Jothir Adithyan > > > > > **Runnable Version** > https://replit.com/@Adithyan71/GetOr > > > > **Code Samples.** > > ``` > class PlayDict(dict): > def get_or(self, key, arbitrary=None, default=None): > if not self.__contains__( > key > ): # case 1 the key does not exist hence the default value > return default > elif ( > self[key] is None > ): # case 2 key does exist but the value is None return the arb > value > return arbitrary > return self[key] # case 3 the key is present and the value is not > None > > > import contextlib > parent_dict = PlayDict() > parent_dict['k1'] = None > parent_dict['k2'] = {"child_key": "val"} # Parent dict can contain nested > dicts > > with contextlib.suppress(AttributeError): > result = parent_dict.get("k1", {}).get("child_key") # This will raise > AttributeError > > result = parent_dict.get_or("k1", default={}, > arbitrary={}).get("child_key") # This will work > > print(result) > ``` > _______________________________________________ > Python-ideas mailing list -- python-ideas@python.org > To unsubscribe send an email to python-ideas-le...@python.org > https://mail.python.org/mailman3/lists/python-ideas.python.org/ > Message archived at > https://mail.python.org/archives/list/python-ideas@python.org/message/IELDCURRVQXCPGD4EPPLL7MYWJT4XHKV/ > Code of Conduct: http://python.org/psf/codeofconduct/ >
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