Loop through list in dictionary with dictionary values - python

Given a dictionary as such
grouped_data = {"results":[{"id": 101, "name": toto}, {"id": 102, "name": cool}] }
It's a dict that has a list in which it has dictionaries
Hope I'm not confusing you ;), how can I get the results list and loop through each dictionary inside the list to compare the id between them with an if statement.


To get the list:
resultList = grouped_data["results"]
Iterate through the list to get the dictionaries:
for dic in resultList:
# use dic
To get values inside dic:
for dic in resultList:
for key,value in dic.iteritems():
# use key and value
To access the id key, use:
for dic in resultList:
if dic['id'] == somevalue:
# do_something


If you want to "loop through each dictionary inside the list to compare the id between them with an if statement", this is one way to do it.
Example if statement below:
for i in grouped_data["results"]:
if i['id'] > 101:
print (i)
Output:
{'id': 102, 'name': 'cool'}
BTW: You have to convert toto and cool to string unless they are variables which you have declared in your code already.


Not sure what you mean by 'compare the id between them with an if statement'. Many ways to interpret it but here is something that you might use:
print (x for x in grouped_data['results'] if x['id'] > 101).next()
Output:
{'id': 102, 'name': 'cool'}

Related

Merge lists of dictionaries based on matching values in one key

I have a dictionary
dicte = [{'value':3, 'content':'some_string'}, {'value':4, 'content':'some_string1'}, {'value':4, 'content':'some_string2'}, {'value':4, 'content':'some_string3'}, {'value':4, 'content':'some_string4'}, {'value':5, 'content':'some_string5'}]
I want to be able to do an operation on that dictionary so that all the content that got the same values regarding the key "value" are regrouped and generate another dictionary based on that
The result here should be
new_dicte = [{'value':3, 'content':['some_string']}, {'value':4, 'content':['some_string1', 'some_string2', 'some_string3', 'some_string4']}, {'value':5, 'content':['some_string5']}]
What is the best pythonic way to do this ?

"Pythonic" is debatable, but you could build an intermediate dict to group by value:
grouped_by_value = {}
for item in dicte:
if item["value"] not in grouped_by_value:
grouped_by_value[item["value"]] = []
grouped_by_value[item["value"]].append(item["content"])
new_dicte = [{"value": key, "content": val} for key, val in grouped_by_value.items()]
The order of the elements in the new_dicte list will be the order that the values are encountered in the dicte list, assuming you are using a Python version where dicts are sorted by insertion order.
If you want to guarantee a specific ordering for new_dicte, you can sort the items of the grouped_by_value.items(), for example, by increasing "value" key.

Here's one way using dict.setdefault method to collect value-content pairs and unpacking later:
out = {}
for d in dicte:
out.setdefault(d['value'],[]).append(d['content'])
new_dicte = list(map(lambda x: dict(zip(('value','content'), x)), out.items()))
Here's another method that doesn't use an intermediate dictionary:
out = {}
for d in dicte:
if d['value'] not in out:
out[d['value']] = {'value':d['value'], 'content':[d['content']]}
else:
out[d['value']]['content'].append(d['content'])
new_dicte = list(out.values())
Output:
[{'value': 3, 'content': ['some_string']},
{'value': 4,
'content': ['some_string1', 'some_string2', 'some_string3', 'some_string4']},
{'value': 5, 'content': ['some_string5']}]

Best Pythonic is debatable but I would personally go with something like this,
import itertools
from collections import defaultdict
resp = defaultdict(list)
for key,group in itertools.groupby(d, key=lambda x: x["value"]):
for thing in group:
resp[key].append(thing.get("content"))
print(resp)
Output (can be adjusted to the way we want...)
{3: ['some_string'],
4: ['some_string1', 'some_string2', 'some_string3', 'some_string4'],
5: ['some_string5']}

extract specific value from dictionary of list of dictionary

I have dataset like this:
{'project-1': [{'id':'1','name':'john'},{'id':'20','name':'steve'}],
'project-2': [{'id':'6','name':'jack'},{'id':'42','name':'anna'}]}
what I want to extract is the name of all people:
['john','steve','jack','anna']
How to get these list using python?

my_dict = {
'project-1': [{'id':'1','name':'john'},{'id':'20','name':'steve'}],
'project-2': [{'id':'6','name':'jack'},{'id':'42','name':'anna'}]
}
You can use a list comprehension it get the name field from each dictionary contained within the sublists (i.e. within the values of the original dictionary).
>>> [d.get('name') for sublists in my_dict.values() for d in sublists]
['john', 'steve', 'jack', 'anna']

Iterate over the dict, then over the values of the current dict:
for d_ in d.values():
for item in d_:
print item['name']
Or in comprehension
names = [item['name'] for d_ in d.values() for item in d_]
print names
['john', 'steve', 'jack', 'anna']

This should do it.
d = {'project-1': [{'id':'1','name':'john'},{'id':'20','name':'steve'}],
'project-2': [{'id':'6','name':'jack'},{'id':'42','name':'anna'}]}
result = list()
for key in d:
for x in d[key]:
result.append(x['name'])

Many solutions trying same old approach here using two loop:
Here is different approach:
One line solution without any loop:
You can use lambda function with map:
data={'project-1': [{'id':'1','name':'john'},{'id':'20','name':'steve'}],
'project-2': [{'id':'6','name':'jack'},{'id':'42','name':'anna'}]}
print(list(map(lambda x:list(map(lambda y:y['name'],x)),data.values())))
output:
[['john', 'steve'], ['jack', 'anna']]

name_id = {'project-1': [{'id':'1','name':'john'},{'id':'20','name':'steve'}], 'project-2': [{'id':'6','name':'jack'},{'id':'42','name':'anna'}]}
name_id['project-1'][0]['name'] = 'john'
name_id['project-1'][1]['name'] = 'steve'
name_id['project-2'][0]['name'] = 'jack'
name_id['project-2'][1]['name'] = 'anna'
The ['project-1'] gets the value corresponding to the project-1 key in the dictionary name_id. [0] is the list index for the first element in the dictionary value. ['name'] is also a key, but of the dictionary in the first element of the list. It gives you the final value that you want.

Nested lists to nested dicts

I've a list with master keys and a list of list of lists, where the first value of each enclosed list (like 'key_01') shall be a sub key for the corresponding values (like 'val_01', 'val_02'). The data is shown here:
master_keys = ["Master_01", "Master_02", "Master_03"]
data_long = [[['key_01','val_01','val_02'],['key_02','val_03','val_04'], ['key_03','val_05','val_06']],
[['key_04','val_07','val_08'], ['key_05','val_09','val_10'], ['key_06','val_11','val_12']],
[['key_07','val_13','val_14'], ['key_08','val_15','val_16'], ['key_09','val_17','val_18']]]
I would like these lists to be combined into a dictionary of dictionaries, like this:
master_dic = {
"Master_01": {'key_01':['val_01','val_02'],'key_02': ['val_03','val_04'], 'key_03': ['val_05','val_06']},
"Master_02": {'key_04': ['val_07','val_08'], 'key_05': ['val_09','val_10'], 'key_06': ['val_11','val_12']},
"Master_03": {'key_07': ['val_13','val_14'], ['key_08': ['val_15','val_16'], 'key_09': ['val_17','val_18']}
}
What I've got so far is the sub dict:
import itertools
master_dic = {}
servant_dic = {}
keys = []
values = []
for line in data_long:
for item in line:
keys.extend(item[:1])
values.append(item[1:])
servant_dic = dict(itertools.izip(keys, values))
Which puts out a dictionary, as expected.
servant_dic = {
'key_06': ['val_11','val_12'], 'key_04': ['val_08','val_07'], 'key_05': ['val_09','val_10'],
'key_02': ['val_03','val_04'], 'key_03': ['val_05','val_06'], 'key_01': ['val_01','val_02']
}
The problem is, that if I want to add the master_keys to this dictionary, so I get the wanted result, I'd have to do this in a certain order, which would be possible, if each line had a counter like this:
enumerated_dic =
{
0: {'key_01':['val_01','val_02'],'key_02': ['val_03','val_04'], 'key_03': ['val_05','val_06']},
1: {'key_04': ['val_07','val_08'], 'key_05': ['val_09','val_10'], 'key_06': ['val_11','val_12']},
2: {'key_07': ['val_13','val_14'], ['key_08': ['val_15','val_16'], 'key_09': ['val_17','val_18']}
}
I'd love to do this with enumerate(), while each line of the servant_dic is build, but can't figure out how. Since afterwards, i could simply replace the counters 0, 1, 2 etc. with the master_keys.
Thanks for your help.

master_keys = ["Master_01", "Master_02", "Master_03"]
data_long = [[['key_01','val_01','val_02'],['key_02','val_03','val_04'], ['key_03','val_05','val_06']],
[['key_04','val_07','val_08'], ['key_05','val_09','val_10'], ['key_06','val_11','val_12']],
[['key_07','val_13','val_14'], ['key_08','val_15','val_16'], ['key_09','val_17','val_18']]]
_dict = {}
for master_key, item in zip(master_keys, data_long):
_dict[master_key] = {x[0]: x[1:] for x in item}
print _dict

Hope this will help:
{master_key: {i[0]: i[1:] for i in subkeys} for master_key, subkeys in zip(master_keys, data_long)}

My functional approach:
master_dic = dict(zip(master_keys, [{k[0]: k[1::] for k in emb_list} for emb_list in data_long]))
print(master_dic)

You can also use pop and a dict comprehension:
for key, elements in zip(master_keys, data_long):
print {key: {el.pop(0): el for el in elements}}
...:
{'Master_01': {'key_02': ['val_03', 'val_04'], 'key_03': ['val_05', 'val_06']}}
{'Master_02': {'key_06': ['val_11', 'val_12'], 'key_04': ['val_07', 'val_08'], 'key_05': ['val_09', 'val_10']}}
{'Master_03': {'key_07': ['val_13', 'val_14'], 'key_08': ['val_15', 'val_16'], 'key_09': ['val_17', 'val_18']}}

accesing data in a dictionary python

so i have this code:
dic1 = { "data1":1, "data2":2, "data3":3}
dic2 = { "data1":4, "data2":5, "data3":6}
dic3 = { "data1":7, "data2":8, "data3":9}
data = [dic1, dic3, dic2]
how can i access the data in the dictionaries from a function if the input is the list?
so if i have a for:
for x in data:
if x == "dic1":
print dic1["data1"]
print dic1["data2"]
elif x == "dic2":
print dic2["data1"]
and so on......
that will work but only because i know that those dictionaries exist but if another dictionary is created that method will obviously not work, so how can i do it.

Use
for x in data:
for k, v in x.items():
print k, v
So the key here is to use the items method to access to the dictionary's elements.

The first loop iterates over dictionaries, the second loop iterates over keys of dictionary considered by the first loop. Then you print every element:
for dictionary in data:
for key in dictionary:
print dictionary[key]

Using dict keys in python as values in a different dict

I would like to create a "translator" type of dict that would assign values that are keys in different dicts, which are nested, to keys in a dict that I created. The problem I run into is that I can't create a value that represents a nested dict key without having to convert that to a string or some other data type, and when I try to use a string as an index to the nested dict, I get an index error. Ideally, my dict would look something like this:
new_dict{
"new_key_1" : ['subdict1']['subdict2']['old_key_1'],
"new_key_2" : ['subdict1']['subdict2']['old_key_2'],
"new_key_3" : ['subdict1']['subdict3']['old_key_3']
}
Then, for each nested dict, I could generate a new dict object with a simple for loop:
for key, value in new_dict.items() :
user_dict_1[key] = OldDict[value]
The nested dicts are very large and I only need a few fields from each, otherwise I could just use the .copy() function to work with the old dicts.
PS- Any help in rewriting this question to be more readable also appreciated.

You're going to need reduce() for this one...
attrmap = {
"new_key_1": ('subdict1', 'subdict2', 'old_key_1'),
...
}
print reduce(lambda x, y: x[y], attrmap[somekey], old_object)

Are you talking something like this?
from pprint import pprint as pp
subdict1 = {'subdict1_item1':1, 'subdict1_item2':2}
subdict2 = {'subdict2_item1':3, 'subdict2_item2':4}
subdict3 = {'subdict3_item1': 5, 'subdict3_item1':6}
olddict = {
'old_key_1': [subdict1, subdict2],
'old_key_2': [subdict1, subdict2],
'old_key_3': [subdict1, subdict3],
}
newdict = {
'new_key_1': olddict['old_key_1'].append('old_key_1'),
'new_key_2': olddict['old_key_2'].append('old_key_2'),
'new_key_3': olddict['old_key_3'].append('old_key_3'),
}
or this
newdict = {
'new_key_1': 'old_key_1',
'new_key_2': 'old_key_2',
'new_key_3': 'old_key_3',
}
def getnew(newkey, newdict, olddict):
if newkey in newdict:
oldkey = newdict[newkey]
if oldkey in olddict:
preitem = olddict[ oldkey ] # returns a list with two items
item = []
item.append([preitem[0]]) # makes subdict1 wrapped in a list
item.append([preitem[1]]) # makes subdict2/3 wrapped in a list
item.append([oldkey])
return item
else:
raise KeyError('newdict has no matching olddict key')
results to:
pp( getnew('new_key_1', newdict, olddict) )
print
pp( getnew('new_key_2', newdict, olddict) )
print
pp( getnew('new_key_3', newdict, olddict) )
[[{'subdict1_item1': 1, 'subdict1_item2': 2}],
[{'subdict2_item1': 3, 'subdict2_item2': 4}],
['old_key_1']]
[[{'subdict1_item1': 1, 'subdict1_item2': 2}],
[{'subdict2_item1': 3, 'subdict2_item2': 4}],
['old_key_2']]
[[{'subdict1_item1': 1, 'subdict1_item2': 2}],
[{'subdict3_item1': 6}],
['old_key_3']]

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