How to get value from list of dictionaries based on specific key value which does not exist in all d-CodePudding

I have a list of dictionaries that is like this:

{'name': ['Sam'], 'where': ['London']},
{'name': ['Jon'], 'where': ['NY']},
{'name': ['Jon'], 'hobby': ['fifa']},
{'Age': ['20'], 'Country': ['US']},

I do have a dictionary like this that could have a lot of same keys but a lot doesn't have that key too. As in above example, we have name key in first 3, but we don't have name key in the 4th. I am trying to get a list of all values that has key 'name'.

Thanks

CodePudding user response：

What you want is unclear (nor the link to pandas or numpy).

If you simply want the values of name when those exist:

l = [{'name': ['Sam'], 'where': ['London']},
     {'name': ['Jon'], 'where': ['NY']},
     {'name': ['Jon'], 'hobby': ['fifa']},
     {'Age': ['20'], 'Country': ['US']},]

out = [d['name'] for d in l if 'name' in d]
# [['Sam'], ['Jon'], ['Jon']]

# or as flat list
out = [name for d in l if 'name' in d for name in d['name']]
# ['Sam', 'Jon', 'Jon']

# or just the first name
out = [d['name'][0] for d in l if 'name' in d]
# ['Sam', 'Jon', 'Jon']

CodePudding user response：

Here is a way to extract all names:

data = [
    {'name': ['Sam'], 'where': ['London']},
    {'name': ['Jon'], 'where': ['NY']},
    {'name': ['Jon'], 'hobby': ['fifa']},
    {'Age': ['20'], 'Country': ['US']},
]

names = [item['name'][0] for item in data if 'name' in item]
print(names)

Result:

['Sam', 'Jon', 'Jon']

CodePudding user response：

I assume your data is a list of dicts.

data = [{'name': ['Sam'], 'where': ['London']},
{'name': ['Jon'], 'where': ['NY']},
{'name': ['Jon'], 'hobby': ['fifa']},
{'Age': ['20'], 'Country': ['US']},]

You can get a sub list of all elements with a name key like this:

output = [elem for elem in data if elem.get("name")]

CodePudding user response：

There are many ways to do this. One would be:

_list = [{'name': ['Sam'], 'where': ['London']},
{'name': ['Jon'], 'where': ['NY']},
{'name': ['Jon'], 'hobby': ['fifa']},
{'Age': ['20'], 'Country': ['US']}]

print(*(name for d in _list if (name := d.get('name'))))

Output:

['Sam'] ['Jon'] ['Jon']

CodePudding user response：

You can try a list expression:

all_dicts = [{'name': ['Sam'], 'where': ['London']},
{'name': ['Jon'], 'where': ['NY']},
{'name': ['Jon'], 'hobby': ['fifa']},
{'Age': ['20'], 'Country': ['US']}]

dicts_with_name = [d.values() for d in all_dicts if 'name' in d.keys() ]

This extracts all values (for all keys) of those dictionaries in the list that have a name field. If you want the key, value pairs, you can d.items() instead of d.values()