w3resource

Python: Map the values of a list to a dictionary using a function

Python List: Exercise - 220 with Solution

Write a Python program to map the values of a list to a dictionary using a function, where the key-value pairs consist of the original value as the key and the result of the function as the value.

  • Use map() to apply fn to each value of the list.
  • Use zip() to pair original values to the values produced by fn.
  • Use dict() to return an appropriate dictionary.

Sample Solution:

Python Code:

def map_dictionary(itr, fn):
  return dict(zip(itr, map(fn, itr)))
print(map_dictionary([1, 2, 3], lambda x: x * x))

Sample Output: 

{1: 1, 2: 4, 3: 9}

Flowchart:

Flowchart: Map the values of a list to a dictionary using a function.

Visualize Python code execution:

The following tool visualize what the computer is doing step-by-step as it executes the said program:


Python Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: Write a Python program to build a list, using an iterator function and an initial seed value.
Next: Write a Python program to randomize the order of the values of an list, returning a new list.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Follow us on Facebook and Twitter for latest update.

Python: Tips of the Day

Returns True if the provided function returns True for every element in the list, False otherwise:

Example:

def tips_every(lst, fn=lambda x: x):
  return all(map(fn, lst))

print(tips_every([2, 4, 3], lambda x: x > 1))
print(tips_every([1, 2, 3]))

Output:

True
True