# Python Program to convert a list into matrix with size of each row increasing by a number

PythonServer Side ProgrammingProgramming

When it is required to convert a list into matrix with the size of every row increasing by a number, the ‘//’ operator and a simple iteration is used.

## Example

Below is a demonstration of the same

my_list = [42, 45, 67, 89, 99, 10, 23, 12, 31, 43, 60, 1, 0]

print("The list is :")
print(my_list)

my_key = 3
print("The value of key is ")
print(my_key)

my_result = []

for index in range(0, len(my_list) // my_key):
my_result.append(my_list[0: (index + 1) * my_key])

print("The resultant matrix is :")
print(my_result)

## Output

The list is :
[42, 45, 67, 89, 99, 10, 23, 12, 31, 43, 60, 1, 0]
The value of key is
3
The resultant matrix is :
[[42, 45, 67], [42, 45, 67, 89, 99, 10], [42, 45, 67, 89, 99, 10, 23, 12, 31], [42, 45, 67, 89, 99, 10, 23, 12, 31, 43, 60, 1]]

## Explanation

• A list is defined and is displayed on the console.

• A value for key is defined and is displayed on the console.

• An empty list is created.

• A simple iteration is used along with ‘//’ operator, and the element from a specific index multiplied with key.

• This is appended to the empty list.

• This list is displayed as output on the console.

Published on 16-Sep-2021 08:13:11