Python – Convert Uneven Lists into Records

Sometimes, while working with Records, we can have a problem, that we have keys in one list and values in other. But sometimes, values can be multiple in order, like the scores or marks of particular subject. This type of problem can occur in school programming and development domains. Lets discuss certain ways in which this task can be performed. 

Method #1 : Using dictionary comprehension + enumerate() + list slicing The combination of above functions can be used to solve this problem. In this, we iterate using dictionary comprehension and enumerate and form desired result by extracting records values by slicing. 

Python3

# Python3 code to demonstrate working of
# Convert Uneven Lists into Records
# Using dictionary comprehension + enumerate() + list slicing

# initializing lists
test_list1 = ['Nikhil', 'Akash', 'Akshat']
test_list2 = [5, 6, 7, 8, 2, 3, 12, 2, 10]

# printing original lists
print("The original list 1 is : " + str(test_list1))
print("The original list 2 is : " + str(test_list2))

# Convert Uneven Lists into Records
# Using dictionary comprehension + enumerate() + list slicing
temp = len(test_list2) // len(test_list1)
res = {key: test_list2[idx :: temp] for idx, key in enumerate(test_list1)}

# printing result
print("The paired data dictionary : " + str(res))

Output : 

The original list 1 is : [‘Nikhil’, ‘Akash’, ‘Akshat’] The original list 2 is : [5, 6, 7, 8, 2, 3, 12, 2, 10] The paired data dictionary : {‘Nikhil’: [5, 8, 12], ‘Akshat’: [7, 3, 10], ‘Akash’: [6, 2, 2]}

Time Complexity: O(n*n) where n is the total number of values in the list “test_list”. 
Auxiliary Space: O(n) where n is the total number of values in the list “test_list”.

Method #2 : Using list comprehension + zip() This task can also be solved using above functions. In this, we use list comprehension to construct the cumulated score list. In last step we tie both lists together using zip(). 

Python3

# Python3 code to demonstrate working of
# Convert Uneven Lists into Records
# Using list comprehension + zip()

# initializing lists
test_list1 = ['Nikhil', 'Akash', 'Akshat']
test_list2 = [5, 6, 7, 8, 2, 3, 12, 2, 10]

# printing original lists
print("The original list 1 is : " + str(test_list1))
print("The original list 2 is : " + str(test_list2))

# Convert Uneven Lists into Records
# Using list comprehension + zip()
temp = len(test_list2) // len(test_list1)
res = [test_list2[idx :: temp] for idx in range(0, len(test_list1))]
res = dict(zip(test_list1, res))

# printing result
print("The paired data dictionary : " + str(res))

Output : 

The original list 1 is : [‘Nikhil’, ‘Akash’, ‘Akshat’] The original list 2 is : [5, 6, 7, 8, 2, 3, 12, 2, 10] The paired data dictionary : {‘Nikhil’: [5, 8, 12], ‘Akshat’: [7, 3, 10], ‘Akash’: [6, 2, 2]}

Time Complexity: O(n*n), where n is the length of the input list. This is because we’re using the using list comprehension + zip() which has a time complexity of O(n*n) in the worst case.
Auxiliary Space: O(n), as we’re using additional space res other than the input list itself with the same size of input list.