pythondictionaryunset

How can I remove a key from a Python dictionary?


I want to remove a key from a dictionary if it is present. I currently use this code:

if key in my_dict:
    del my_dict[key]

Without the if statement, the code will raise KeyError if the key is not present. How can I handle this more simply?


See Delete an element from a dictionary for more general approaches to the problem of removing a key from a dict (including ones which produce a modified copy).


Solution

  • To delete a key regardless of whether it is in the dictionary, use the two-argument form of dict.pop():

    my_dict.pop('key', None)
    

    This will return my_dict[key] if key exists in the dictionary, and None otherwise. If the second parameter is not specified (i.e. my_dict.pop('key')) and key does not exist, a KeyError is raised.

    To delete a key that is guaranteed to exist, you can also use

    del my_dict['key']
    

    This will raise a KeyError if the key is not in the dictionary.