How do I get the values for ALL items in my python dictionary that have a certain key?

Question

I have a dictionary that's formatted like this (it's missing the values, obv):

{'expand': ,
 'issues': [{'expand': ,
             'fields': {'created': ,
                        'issuetype': {'avatarId': ,
                                      'description': ,
                                      'iconUrl': ,
                                      'id': ,
                                      'name': ,
                                      'self': ,
                                      'subtask': },
                        'priority': {'iconUrl': ,
                                     'id': ,
                                     'name': ,
                                     'self': },
                        'project': {'avatarUrls': {'16x16': ,
                                                   '24x24': ,
                                                   '32x32': ,
                                                   '48x48': },
                                    'id': ,
                                    'key': ,
                                    'name': ,
                                    'projectCategory': {'description': ,
                                                        'id': ,
                                                        'name': ,
                                                        'self': },
                                    'projectTypeKey': ,
                                    'self': },
                        'status': {'description': ,
                                   'iconUrl': ,
                                   'id': ,
                                   'name': ,
                                   'self': ,
                                   'statusCategory': {'colorName': ,
                                                      'id': ,
                                                      'key': ,
                                                      'name': ,
                                                      'self': }}},
             'id': ,
---->        'key': ,
             'cccc': },

I need to get access to all the values that the key is "key".

jira_key = dict["issues"][0]["key"]

This grabs the key for the first one, but there's like 60+ that I need. I've tried various things I've found and nothing seems to be successful.

Note: Not a developer :)

Are you filtering just the `dict['issues']` list, or must you find any dictionary anywhere in the structure? — Martijn Pieters, Jan 15 '19 at 16:33
If you are just trying to get `dict['issues'][0]['key']`, `dict['issues'][1]['key']`, etc (just the `key` values in the `dict['issues']` list), then search `for... loop` and you will be on your way. — benvc, Jan 15 '19 at 16:36
So lets say you have dict: `some_dict = {'issues': [{'key':'bla'}, {'smth_else': 'bla'}]}` you can get filtered one like this: `new_dict = {'issues': [d for d in some_dict['issues'] if 'key' in d]}` Not sure if you if you want to get 'key' named 'key' so just for reference. If you want to get all the keys from python dict you can do `some_dict.keys()` — The Hog, Jan 15 '19 at 16:46
I'm going to assume that you just want to extract the values for `key` from a single list. See the duplicate for that. — Martijn Pieters, Jan 15 '19 at 17:01
Well I do want to get values from a list, but I've already got the first one. And from the looks of it, all the ticket data is nested in a dictionary within the list. So I'm not sure how to tell it to give me all values for the key "key", looping would've been a good idea. I don't know how to loop through a dictionary though? — bombasticbri, Jan 15 '19 at 22:18

Uvar · Accepted Answer · 2019-01-16T15:05:56.103

There are, as always, multiple ways which do the trick.

One of these ways, assuming for a second here the JIRA keys you need are only issue keys, not project or projectCategory keys, is by using the itemgetter:

from operator import itemgetter as itg
key_finder = itg('key')
my_values = list(map(key_finder, DICT_NAME['issues']))

The itemgetter functions as a wrapper around a comprehension and essentially returns tuple(obj[i] for i in items) where items is the collection of arguments passed into itemgetter. Therefore, itemgetter('key', 'id') would wrap a search for 'key' and 'id' and the function applied to a dictionary would return it's 'key' and 'id' values, in this case only 'key' was needed.

map(function, iterable) applies the function sequentially to items in iterable, e.g. function(iterable[0]); function(iterable[1]) etc.

In your case, with having to loop multiple times and combine results:

from functools import reduce
issue_key_values = reduce(lambda x,y: x+y, [list(map(key_finder, ll['issues'])) for ll in jira_list])

The reduction operator, from its docstring:

Apply a function of two arguments cumulatively to the items of a sequence, from left to right, so as to reduce the sequence to a single value.

The other steps are evaluation of generator expressions and loop comprehensions, which you can find plenty of material on around this site (and Google).

So this totally worked, but I have my code looping the data, since I can only pull x amount of tickets at a time. `loops = math.ceil(total/max)` is what I have to tell me how many times the loop needs to happen. I need to iterate on this, too. But I'm not sure how. `jira_keys = list(map(key_finder, jira_list[0]['issues'])) + list(map(key_finder, jira_list[1]['issues']))` is what is working right now. But I want it to go through the list per how many times my `loop` variable says. — bombasticbri, Jan 16 '19 at 14:15
Ah! That's beautiful, thank you! But, if you're willing, can you explain some pieces of it, I just want to understand it better. :) — bombasticbri, Jan 16 '19 at 14:45
If you like the solution, you can clear the negative vote on it / accept it as the working answer.. But I'll add some fluff — Uvar, Jan 16 '19 at 14:57

How do I get the values for ALL items in my python dictionary that have a certain key?

1 Answers1