CODEWITHSUNDEEP
python
carlaodev
carlaodev

Reputation: 641

How to group items in a list of dictionaries by matching values in python

I have the following an array of dictionaries:

dictionaty =[{'name': 'fire', 'command': '1;2;3;4'}, 
{'name': 'brain', 'command': '2;2;3;4'}, {'name': 'word', 'command': '1;3;4;5'},
{'name': 'cellphone', 'command': '6;1;3;4'}, {'name': 'ocean', 'command': '9;3;7;4'},

how do I get the dictionaries that have the command with the second and third value after ';' respectively equal? For example: 'command': '1;2;3;4' is equals 'command': '2;2;3;4'

Upvotes: 0

Views: 324

Answers (2)

Cory Kramer
Cory Kramer

Reputation: 117856

You can use itertools.groupby. You can construct a lambda expression that looks for the value corresponding to the 'command' key, then finds the [1] and [2] elements of splitting on the ';' character.

d =[{'name': 'fire', 'command': '1;2;3;4'},
    {'name': 'brain', 'command': '2;2;3;4'},
    {'name': 'word', 'command': '1;3;4;5'},
    {'name': 'cellphone', 'command': '6;1;3;4'},
    {'name': 'ocean', 'command': '9;3;7;4'}]

import itertools
groups = itertools.groupby(d, lambda i: i['command'].split(';')[1:3])

for key, group in groups:
    print(list(group))

Output

[{'name': 'fire', 'command': '1;2;3;4'}, {'name': 'brain', 'command': '2;2;3;4'}]
[{'name': 'word', 'command': '1;3;4;5'}]
[{'name': 'cellphone', 'command': '6;1;3;4'}]
[{'name': 'ocean', 'command': '9;3;7;4'}]

To find groups that had more than one member, you need one more step:

for key, group in groups:
    groupList = list(group)
    if len(groupList) > 1:
        print(groupList)

[{'command': '1;2;3;4', 'name': 'fire'}, {'command': '2;2;3;4', 'name': 'brain'}]

Upvotes: 2

Nir Alfasi
Nir Alfasi

Reputation: 53525

You can iterate the items and for each item check the items to follow and compare the last part of 'command':

dictionaty =[{'name': 'fire', 'command': '1;2;3;4'}, 
             {'name': 'brain', 'command': '2;2;3;4'}, 
             {'name': 'word', 'command': '1;3;4;5'},
             {'name': 'cellphone', 'command': '6;1;3;4'}, 
             {'name': 'ocean', 'command': '9;3;7;4'}]

for i, itm in enumerate(dictionaty):
    itm_last_part = itm['command'].split(';')[2:]
    for second in dictionaty[i+1:]:
        second_last_part = second['command'].split(';')[2:]
        if itm_last_part == second_last_part:
            print itm, second, "are equal"

OUTPUT

{'command': '1;2;3;4', 'name': 'fire'} {'command': '2;2;3;4', 'name': 'brain'} are equal
{'command': '1;2;3;4', 'name': 'fire'} {'command': '6;1;3;4', 'name': 'cellphone'} are equal
{'command': '2;2;3;4', 'name': 'brain'} {'command': '6;1;3;4', 'name': 'cellphone'} are equal

Upvotes: 0

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