Python list of dictionaries search

Question

Assume I have this:

[
{"name": "Tom", "age": 10},
{"name": "Mark", "age": 5},
{"name": "Pam", "age": 7}
]

and by searching "Pam" as name, I want to retrieve the related dictionary: {name: "Pam", age: 7}

How to achieve this ?

Answer 1

You can try this:

''' lst: list of dictionaries '''
lst = [{"name": "Tom", "age": 10}, {"name": "Mark", "age": 5}, {"name": "Pam", "age": 7}]

search = raw_input("What name: ") #Input name that needs to be searched (say 'Pam')

print [ lst[i] for i in range(len(lst)) if(lst[i]["name"]==search) ][0] #Output
>>> {'age': 7, 'name': 'Pam'} 

Answer 2

You can use a list comprehension:

def search(name, people):
    return [element for element in people if element['name'] == name]

Answer 3

You can use a generator expression:

>>> dicts = [
...     { "name": "Tom", "age": 10 },
...     { "name": "Mark", "age": 5 },
...     { "name": "Pam", "age": 7 },
...     { "name": "Dick", "age": 12 }
... ]

>>> next(item for item in dicts if item["name"] == "Pam")
{'age': 7, 'name': 'Pam'}

Answer 4

@Frédéric Hamidi's answer is great. In Python 3.x the syntax for .next() changed slightly. Thus a slight modification:

>>> dicts = [
     { "name": "Tom", "age": 10 },
     { "name": "Mark", "age": 5 },
     { "name": "Pam", "age": 7 },
     { "name": "Dick", "age": 12 }
 ]
>>> next(item for item in dicts if item["name"] == "Pam")
{'age': 7, 'name': 'Pam'}

As mentioned in the comments by @Matt, you can add a default value as such:

>>> next((item for item in dicts if item["name"] == "Pam"), False)
{'name': 'Pam', 'age': 7}
>>> next((item for item in dicts if item["name"] == "Sam"), False)
False
>>>

Answer 5

This looks to me the most pythonic way:

people = [
{'name': "Tom", 'age': 10},
{'name': "Mark", 'age': 5},
{'name': "Pam", 'age': 7}
]

filter(lambda person: person['name'] == 'Pam', people)

result (returned as a list in Python 2):

[{'age': 7, 'name': 'Pam'}]

Note: In Python 3, a filter object is returned. So the python3 solution would be:

list(filter(lambda person: person['name'] == 'Pam', people))

Answer 6

Simply using list comprehension:

[i for i in dct if i['name'] == 'Pam'][0]

Sample code:

dct = [
    {'name': 'Tom', 'age': 10},
    {'name': 'Mark', 'age': 5},
    {'name': 'Pam', 'age': 7}
]

print([i for i in dct if i['name'] == 'Pam'][0])

> {'age': 7, 'name': 'Pam'}