CODEWITHSUNDEEP
python
Heyya
Heyya

Reputation: 57

How to check whether a key exist inside a nested dictionary and if yes delete

I have this main_dict created and want to see if main_dict[x]["Description"] exists or not, and if yes, then delete it. Where x is 'pins', 'nails', 'board', etc ...

main_dict = {
'pins':
    {
        'Category': ['General'],
        'Contact': ['Mark'],
        'Description': ['This', 'is', 'a']
    },
'nails':
    {
        'Category': ['specific'],
        'Contact': ['Jon'],
        'Description': ['This', 'is', 'a', 'description']
    },
'board':
    {
        'Category': ['General'],
        'Contact': ['Mark'],
        'Description': ['This', 'is', 'a']
    },
'hammer':
    {
        'Category': ['tools'],
        'Contact': ['Jon'],
        'Description': ['This', 'is', 'a', 'description']
    }
}

I tried this:

for x in main_dict:
   del main_dict[x]["Description"]

This returns error if main_dict[x]["Description"] does not exist.

Also this does not work:

if main_dict[x]["Description"] in mainDict[x]:
     del main_dict[x]["Description"]

Upvotes: 0

Views: 75

Answers (4)

martineau
martineau

Reputation: 123473

This would remove it from any sub-dictionaries that contain it:

main_dict = {
    'pins':
        {
            'Category': ['General'],
            'Contact': ['Mark'],
            'Description': ['This', 'is', 'a']
        },
    'nails':
        {
            'Category': ['specific'],
            'Contact': ['Jon'],
            'Description': ['This', 'is', 'a', 'description']
        },
    'board':
        {
            'Category': ['General'],
            'Contact': ['Mark'],
            'Description': ['This', 'is', 'a']
        },
    'hammer':
        {
            'Category': ['tools'],
            'Contact': ['Jon'],
            'Description': ['This', 'is', 'a', 'description']
        }
}

for key, value in main_dict.items():
    if isinstance(value, dict) and 'Description' in value:
        del value['Description']

Result:

{
    'pins':
        {
            'Category': ['General'],
            'Contact': ['Mark'],
        },
    'nails':
        {
            'Category': ['specific'],
            'Contact': ['Jon'],
        },
    'board':
        {
            'Category': ['General'],
            'Contact': ['Mark'],
        },
    'hammer':
        {
            'Category': ['tools'],
            'Contact': ['Jon'],
        }
}

Upvotes: 0

leoschet
leoschet

Reputation: 1866

To check if a key is in a dictionary try if key in dict to check in nested dictionaries you follow the same logic:

for key in main_dict:
    if 'Description' in main_dict[key]:
        # do something

About removing an element, you should indeed use the del statement. I copied your main_dict, and ran the same as you:

for x in main_dict: 
    del main_dict[x]['Description']

Maybe you're trying to remove it twice?

Upvotes: 0

vishes_shell
vishes_shell

Reputation: 23504

You simply use pop() method with default argument(e.g. None) to omit checking if "Description" exist as key.

for i in main_dict:
    main_dict[i].pop("Description", None)

Note: it's not a good practice to change iterable object while iterating over it.

Upvotes: 4

OneRaynyDay
OneRaynyDay

Reputation: 3968

Here's a simple solution:

for x in main_dict:
    if "Description" in main_dict[x]:
        main_dict[x].pop("Description")

Upvotes: 2

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