How to Extract Data from Dictionary in the List

Extracting dictionary items embedded in a list

You can use list comprehension:

t = [{'a': 1.0, 'b': 2.0},
 {'a': 3.0, 'b': 4.0},
 {'a': 5.0, 'b': 6.0},
 {'a': 7.0, 'b': 9.0},
 {'a': 9.0, 'b': 0.0}]
new_list = [i["a"] for i in t]

Output:

[1.0, 3.0, 5.0, 7.0, 9.0]

Since this solution uses a for-loop, you can use map instead:

x = list(map(lambda x: x["a"], t))

Output:

[1.0, 3.0, 5.0, 7.0, 9.0]

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Performance-wise, you prefer to use list-comprehension solution rather the map one.

>>> timeit('new_list = [i["a"] for i in t]', setup='from __main__ import t', number=10000000)
4.318223718035199

>>> timeit('x = list(map(lambda x: x["a"], t))', setup='from __main__ import t', number=10000000)
16.243124993163093


def temp(p):
    return p['a']

>>> timeit('x = list(map(temp, t))', setup='from __main__ import t, temp', number=10000000)
16.048683850689343

There is a slightly difference when using a lambda or a regular function; however, the comprehension execution takes 1/4 of the time.

How to extract value from dict inside list in python

NOTE: For adding the total, read till the end

Firstly, to get a value of a certain value in a dict, the indexing is as follows

dict["key"] and not dict.["key"]

Secondly, to append something to a list use parenthesis not square brackets. So,

.append(x) not .append[x]

Fixing these two things we have as of now:

dictlist = { "g1" : [], "g2" : [] , "g3" : [] }

a = ["a", 23]
a1 = ["asd", 3]
a2 = ["asdf", 10]
a3 = ["adg", 5]

b1 = ["df", 5]
b2 = ["dfg", 1]

c = ["dfg", 50]

dictlist["g1"].append(a)
dictlist["g1"].append(a1)
dictlist["g1"].append(a2)
dictlist["g1"].append(a3)

dictlist["g2"].append(b1)
dictlist["g2"].append(b2)

dictlist["g3"].append(c)

#Now, you want to print the key of the dict as the heading, so our first loop will be:
for heading in dict.keys(): # dictlist.keys() returns a list of all the keys
    print(heading)

#The next thing you want is to print the values of the respective key seperated by ",":
    for value in dict[heading]:
        print(*value, sep=",")  # we can use the sep keyword to print it as we require

# The at the end, an empty print() to seperate the headings
    print()

Output:

g1
a, 23
asd, 3
asdf, 10
adg, 5

g2
df, 5
dfg, 1

g3
dfg, 50

Now, for adding the total:

for heading in dict.keys():
    print(heading)

    total = 0  # We make a variable, becomes zero for every heading
    for value in dict[heading]: # value is a list like ["a", 23], has str and int.. So;
        total += sum(item for item in value if type(item) == int)
        print(*value, sep=",")

    #print the total before starting the next heading
    print("total," total)
    print()

Output:

g1
a, 23
asd, 3
asdf, 10
adg, 5
total,  41

g2
df, 5
dfg, 1
total,  6

g3
dfg, 50
total,  50

Python extract values of a key from a list of lists of dictionaries

You can do this with a list comprehension:

pValues = [[d["p"] for d in row] for row in data]

This iterates through each row of your list of lists of dictionaries, then iterates through each dictionary in the row and gets the value of "p" for each of them. (Note data is your list of lists of dictionary)

How to extract data from a list of dictionaries from a filter

You can write a function and use filter(...) on the list:

lst = [{'title': 'aaa', 'responses': '1 response', 'url': 'https://www.example.com/aaa'}, {'title': 'bbb', 'responses': '4 responses', 'url': 'https://www.example.com/bbb'}, {'title': 'ccc', 'responses': '2 responses', 'url': 'https://www.example.com/ccc'}, {'title': 'ddd', 'responses': '8 responses', 'url': 'https://www.example.com/ccc'}, {'title': 'eee', 'responses': '2 responses', 'url': 'https://www.example.com/eee'}]

def few_responses(item):
    number, _ = item['responses'].split()
    if (int(number) < 2):
        return True
    else:
        return False


for item in filter(few_responses, lst):
    print(item["url"])

Alternatively you can use a list comprehension that does the same:

urls = [item["url"]
        for item in lst
        for number, _ in [item["responses"].split()]
        if (int(number) < 2)]
print(urls)

How can I extract all values from a dictionary in Python?

If you only need the dictionary keys 1, 2, and 3 use: your_dict.keys().

If you only need the dictionary values -0.3246, -0.9185, and -3985 use: your_dict.values().

If you want both keys and values use: your_dict.items() which returns a list of tuples [(key1, value1), (key2, value2), ...].

how can I extract values from this dictionary in Python?

Also, assuming your file has new line delimited dictionaries, using below code solved the issue:

import json
fo = open(r"C:\Users\Downloads\test.txt", "r")
for each_line in fo.readlines():
    print(json.loads(json.loads(each_line)['message'])['first_name'])
    print(json.loads(json.loads(each_line)['message'])['last_name'])
    print(json.loads(json.loads(each_line)['message'])['id'])
    print(json.loads(json.loads(each_line)['message'])['phone'])

Extracting data from dictionary with a list inside (with more dicts inside)

TRY:

import json
import pandas as pd

with open('<json_file_path_here>', 'r') as f:
    d = json.loads(f.read())
    
df = pd.DataFrame(d['Country'])

OUTPUT:

  Team   color
0    1    blue
1    2     red
2    3  orange

How to Extract Values from Dictionaries and Create Lists From Them

That can be done with a couple of comprehensions like:

Code:

def get_values_as_tuple(dict_list, keys):
    return [tuple(d[k] for k in keys) for d in dict_list]

How?

How does this work? This is a nested comprehension. Let's go from the inside out, and start with:

tuple(d[k] for k in keys)

This creates a tuple of all of the elements in d that are specified via k in keys. So, that is nice, but what the heck are d, k and keys?

• keys is passed to the function, and are the keys we will look for in our dicts.

• k is the individual values in keys from k in keys.

• d is the individual dicts in dict_list from d in dict_list.

The outer comprehension builds a list of the tuples discussed above:

[tuple(d[k] for k in keys) for d in dict_list]

Test Code:

dictionaries = [{'id': 1, 'name': 'test1', 'description': 'foo'},
                {'id': 2, 'name': 'test2', 'description': 'bar'}]


def get_values_as_tuple(dict_list, keys):
    return [tuple(d[k] for k in keys) for d in dict_list]

print(get_values_as_tuple(dictionaries, ('id', 'name', 'description')))

Results:

[(1, 'test1', 'foo'), (2, 'test2', 'bar')]

Extract values from dictionary to list in Python

Just do :

>>> out = []
>>> for ele in Reference['Data']: 
        out.append(ele['red']) 

>>> out
=> ['WA-1a9asd4sdfdas', 'WA-150824979asd4', 'WA-1508249792364']

Or, a single liner using List comprehension :

>>> [ ele['red'] for ele in Reference['Data'] ]
=> ['WA-1a9asd4sdfdas', 'WA-150824979asd4', 'WA-1508249792364']

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