Program to Map Two Lists into a Dictionary

Python Program to Map Two Lists into a Dictionary using Zip(), Append() Functions | How to Combine Two Lists into a Dictionary?

/ Python / By

Our website provided core java programs examples with output aid beginners and expert coders to test their knowledge gap and learn accordingly.

Dictionaries in Python: In Python, a dictionary dict is a one-to-one mapping; it includes a set of (key, value) pairs, with each key mapped to a value. It exemplifies a hash map or hash table (from Computer Science). Each key denotes a value and is separated by a colon (:).

Curly brackets are used to define a dictionary. The value to the left of the colon is known as the key, while the value to the right of the colon is known as the value. A comma separates each (key, value) pair.

Python Programming Examples on How to Map Two Lists into a Dictionary

Example 1:

Input:

Enter number of elements to be added to the dictionary = 8
Enter the keys : 
Enter the key1 = hello
Enter the key2 = this
Enter the key3 = is
Enter the key4 = btechgeeks
Enter the key5 = online
Enter the key6 = coding
Enter the key7 = python
Enter the key8 = platform
Enter the Values : 
Enter the value1 = 45
Enter the value2 = 82
Enter the value3 = 125
Enter the value4 = 962
Enter the value5 = 712
Enter the value6 = 100
Enter the value7 = 852
Enter the value8 = 965

Output:

The resultant dictionary with keys = ['hello', 'this', 'is', 'btechgeeks', 'online', 'coding', 'python', 'platform'] 
values = [45, 82, 125, 962, 712, 100, 852, 965] :
{'hello': 45, 'this': 82, 'is': 125, 'btechgeeks': 962, 'online': 712, 'coding': 100, 'python': 852, 'platform': 965}

Example 2:

Input:

Enter number of elements to be added to the dictionary = 5
Enter the keys : 
Enter the key1 = good
Enter the key2 = morning
Enter the key3 = python
Enter the key4 = script
Enter the key5 = code
Enter the Values : 
Enter the value1 = 745
Enter the value2 = 123
Enter the value3 = 985
Enter the value4 = 100
Enter the value5 = 585

Output:

The resultant dictionary with keys = ['good', 'morning', 'python', 'script', 'code'] 
values = [745, 123, 985, 100, 585] :
{'good': 745, 'morning': 123, 'python': 985, 'script': 100, 'code': 585}

Python Program to Map Two Lists into a Dictionary

Mapping Two Lists into a Dictionary using zip() ,append() Functions

Approach:

  1. Declare two empty lists one to store keys and the other to store values.
  2. Consider using a for loop to accept values for both lists.
  3. Scan the number of elements to be added to the dictionary and store it in a variable.
  4. Scan the values into the list and insert them into the list using another for loop.
  5. Repeat steps 4 and 5 for the values list as well.
  6. Zip the two lists together and use dict() to turn them into a dictionary.
  7. Print the dictionary.
  8. Exit of program.

Write a Python Program to Map Two Lists into a Dictionary?

# Declare two empty lists one to store keys and the other to store values.
keyslist = []
valueslist = []
# Scan the number of elements to be added to the dictionary and store it in a variable.
numb = int(input("Enter number of elements to be added to the dictionary = "))
print("Enter the keys : ")
for p in range(numb):
  # scanning the keys
    keyelement = input("Enter the key"+str(p+1)+" = ")
    keyslist.append(keyelement)
print("Enter the Values : ")
for p in range(numb):
    # scanning the values
    valueelement = int(input("Enter the value"+str(p+1)+" = "))
    valueslist.append(valueelement)
# Zip the two lists together and use dict() to turn them into a dictionary.
resultdict = dict(zip(keyslist, valueslist))
# printing the dictionary
print("The resultant dictionary with keys =",
      keyslist, "values =", valueslist, ":")
print(resultdict)

Python Program to Map Two Lists into Dictionary Using Zip and Append Functions

Output:

Enter number of elements to be added to the dictionary = 8
Enter the keys : 
Enter the key1 = hello
Enter the key2 = this
Enter the key3 = is
Enter the key4 = btechgeeks
Enter the key5 = online
Enter the key6 = coding
Enter the key7 = python
Enter the key8 = platform
Enter the Values : 
Enter the value1 = 45
Enter the value2 = 82
Enter the value3 = 125
Enter the value4 = 962
Enter the value5 = 712
Enter the value6 = 100
Enter the value7 = 852
Enter the value8 = 965
The resultant dictionary with keys = ['hello', 'this', 'is', 'btechgeeks', 'online', 'coding', 'python', 'platform'] values = [45, 82, 125, 962, 712, 100, 852, 965] :
{'hello': 45, 'this': 82, 'is': 125, 'btechgeeks': 962, 'online': 712, 'coding': 100, 'python': 852, 'platform': 965}

How to Combine Two Lists into a Dictionary Python?

  • The number of elements in the list must be entered by the user and saved in a variable.
  • The user must assign values to the equal number of entries in the list.
  • The append function takes each element from the user and appends it to the end of the list as many times as the number of elements taken is.
  • The identical steps as in 2 and 3 are taken for the second value list.
  • The zip() function is used to combine the two lists.
  • Using dict, the zipped lists are then combined to make a dictionary ().
  • The dictionary created by combining the two lists is then printed.

Python Program to Map Two lists into a Dictionary using Dictionary Comprehension

Dictionary Comprehension is a technique used to create a dictionary in Python. In this process, we will combine two sets of data either in lists or arrays. It is a simple approach for creating dictionaries and uses pointed brackets({}).

items = ['book', 'pen', 'paper']
quantities = [5, 10, 25]
items_dict = {key:value for key, value in zip(items, quantities)}

print(items_dict)

Output:

{'book': 5, 'pen': 10, 'paper': 25}

How to Combine Two List and Convert into Dictionary using For Loop?

fruits = ['Orange', 'Pomegranate', 'Banana','Guava']
price = [80, 70, 112, 66]

fruits_price = zip(fruits, price)

# create dictionary
fruits_dict = {}

for key, value in fruits_price:
if key in fruits_dict:
# handling duplicate keys
pass
else:
fruits_dict[key] = value

print(fruits_dict)

Output:

{'Orange': 80, 'Pomegranate': 70, 'Banana': 112, 'Guava': 66}

Related Programs: