Convert two lists into a dictionary

Question

Imagine that you have:

keys = [\'name\', \'age\', \'food\']
values = [\'Monty\', 42, \'spam\']

What is the simplest way to produce the foll

Answer 1

Although there are multiple ways of doing this but i think most fundamental way of approaching it; creating a loop and dictionary and store values into that dictionary. In the recursive approach the idea is still same it but instead of using a loop, the function called itself until it reaches to the end. Of course there are other approaches like using dict(zip(key, value)) and etc. These aren't the most effective solutions.

y = [1,2,3,4]
x = ["a","b","c","d"]

# This below is a brute force method
obj = {}
for i in range(len(y)):
    obj[y[i]] = x[i]
print(obj)

# Recursive approach 
obj = {}
def map_two_lists(a,b,j=0):
    if j < len(a):
        obj[b[j]] = a[j]
        j +=1
        map_two_lists(a, b, j)
        return obj
      


res = map_two_lists(x,y)
print(res)

Both the results should print

{1: 'a', 2: 'b', 3: 'c', 4: 'd'}  

Answer 2

keys = ['name', 'age', 'food']
values = ['Monty', 42, 'spam']
index=np.arange(0,len(keys)-1)

df=pd.DataFrame(list(zip(keys,values)), columns=['keys','values'])
df.set_index('keys')
print(df.head())

data_dict = df.iloc[index].set_index('keys')['values'].to_dict() 
print(data_dict)

zip creates a generator of parallel values list() instantiates the full generator and passing that into the dataframe which converts the whole expression. resulting output:

two lists:

    keys values
 0  name  Monty
 1   age     42
 2  food   spam
 

Output: dictionary

 {'name': 'Monty', 'age': 42}

Answer 3

A more natural way is to use dictionary comprehension

keys = ('name', 'age', 'food')
values = ('Monty', 42, 'spam')    
dict = {keys[i]: values[i] for i in range(len(keys))}

Answer 4

Here is also an example of adding a list value in you dictionary

list1 = ["Name", "Surname", "Age"]
list2 = [["Cyd", "JEDD", "JESS"], ["DEY", "AUDIJE", "PONGARON"], [21, 32, 47]]
dic = dict(zip(list1, list2))
print(dic)

always make sure the your "Key"(list1) is always in the first parameter.

{'Name': ['Cyd', 'JEDD', 'JESS'], 'Surname': ['DEY', 'AUDIJE', 'PONGARON'], 'Age': [21, 32, 47]}

Answer 5

you can use this below code:

dict(zip(['name', 'age', 'food'], ['Monty', 42, 'spam']))

But make sure that length of the lists will be same.if length is not same.then zip function turncate the longer one.

Answer 6

Solution as dictionary comprehension with enumerate:

dict = {item : values[index] for index, item in enumerate(keys)}

Solution as for loop with enumerate:

dict = {}
for index, item in enumerate(keys):
    dict[item] = values[index]