How to Convert a Map to a List in Python

In Python, sometimes you may need to convert a map object to a list for simpler manipulation or data processing.

A map object in Python is a built-in function that applies a function on all the items of an iterator given as input and returns a map object that contains the results.

This article will guide you on how to convert a map object to a list in Python with simple steps.

What you will need

To follow this tutorial, you will need a basic understanding of Python and its in-build functions including the map function and the list function. A Python Integrated Development Environment (IDE) or compiler would also be important to run the codes.

Step 1: Create a Function

First, define a function that you would like to apply to the items in your list. For instance:

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# Python 3
def multiply(n):
  return n*n

In this case, the function multiply(n) performs the operation of squaring a number.

Step 2: Apply the Function Using Map

Next, apply the function to your list items using the map function.

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numbers = [1, 2, 3, 4]
result = map(multiply, numbers)

Here, the map function applies the multiply(n) function to each item in the list numbers.

Step 3: Convert Map Object to List

Finally, use the list function to convert the map object to a list:

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final_list = list(result)

This line of code converts the map object result to a list.

Complete Code

Here is the complete code that combines all of the steps above:

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# Python 3
def multiply(n):
  return n*n
 
numbers = [1, 2, 3, 4]
result = map(multiply, numbers)
final_list = list(result)
 
print(numbers)
print(result)
print(final_list)

Output

[1, 2, 3, 4]
<map object at 0x00000183BC2F7130>
[1, 4, 9, 16]

Conclusion

In conclusion, converting a map to a list in Python is a straightforward process once you understand the map and list functions.

The process involves defining a function, applying the function to the items in a list using the map function, and then converting the map object to a list with the list function.

This tutorial provides a simple method to achieve this, thus enhancing your Python programming skills and capabilities.