Python json delete key if exists
Approach: calculate keys to remove, mutate dictLet's call Show
You calculate up front all the affected items and operate on them. Approach: calculate keys to keep, make new dict with those keysI prefer to create a new dictionary over mutating an existing one, so I would probably also consider this:
or: A dictionary is a very powerful data collection in Python. Dictionaries help make database operations faster. You can append items to an existing dictionary and remove them as well. In this blog post, we will learn how to delete "keys" using two methods:
What is a Dictionary in Python?A dictionary is an unordered collection of items. The items are defined using key-value pairs. Keys map to their corresponding item in the list. Whenever an item needs to be queried, we can do this using its key. For example, Here's the syntax for declaring a dictionary in Python:
In our examples, we will use the below dictionary: Declare a dictionary named my_dict
Remove a key using del.You can remove a key using the
Let's delete a key
in our dictionary
After we delete that key, we can see that the key But, what happens if you try to delete a key that does not exist? Let's try to delete the key We received a traceback error. This is valid as the key does not exist. One drawback of However, we can handle this exception using the second method. Remove a key using pop()The second way to remove a key is using the
Where,
Now, if we try to delete Now, let's try to delete an existing key with Here, the key:Book is successfully deleted. One advantage of How to set a custom message:Let's try to delete 'Book' again. We are expecting an error, so let's set a return message. Here, As "Book" was already deleted, we are getting the error messageAnother advantage is that it also returns the value of the key in addition to performing a delete
operation. If you need to know the value of a deleted key, then ConclusionIn this tutorial, we learned how to create a dictionary in Python. We also focused on how to delete key:value pairs in a dictionary. I hope you found this tutorial helpful. Let's connect on Twitter! Read my other posts here. Let's chat on Discord. Learn to code for free. freeCodeCamp's open source curriculum has helped more than 40,000 people get jobs as developers. Get started How do you delete a key in Python?To remove a key from a dictionary in Python, use the pop() method or the “del” keyword. Both methods work the same in that they remove keys from a dictionary. The pop() method accepts a key name as argument whereas “del” accepts a dictionary item after the del keyword.
How do you delete a keyTo delete a key, value pair in a dictionary, you can use the del method. A disadvantage is that it gives KeyError if you try to delete a nonexistent key. So, instead of the del statement you can use the pop method. This method takes in the key as the parameter.
How do I remove a key from a list in Python?How to Remove an Element from a List Using the remove() Method in Python. To remove an element from a list using the remove() method, specify the value of that element and pass it as an argument to the method.
How do I delete a key?Right-click the key and select Delete from the pop-up menu that appears. Select Edit > Keys > Delete Keys. If Time Range-All is on in the Delete Keys options, all keys for the current object are deleted.
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