  # Python program for creating a list centered at zero

NumPy | Python Methods and Functions

Examples :

`  Input:  limit = 1, diff = 0.5  Output:  [-1, -0.5 , 0.0, 0.5, 1] ​​ Input:  limit = 25, diff = 5  Output:  [-25, -20, -15, -10, -5, 0, 5, 10, 15, 20, 25] `

Approach # 1: The naive approach

This is the naive approach to the above problem. First, create an empty list & # 39; lst & # 39; and then we use a while loop to add the next integer with a difference of & # 39; diff & # 39 ;.

 ` # Python3 conversion program ` ` # list to dictionary `   ` def ` ` create (limit, diff): `   ` lst ` ` = ` ` [` ` - ` ` limit] ` ` while ` ` lst [` ` - ` ` 1 ` `] & lt; limit: ` ` lst.append (lst [` ` - ` ` 1 ` `] ` ` + ` ` diff) ` ` lst [` ` - ` ` 1 ` `] ` ` = ` ` limit ` ` return ` ` lst `   ` # Driver code ` ` limit ` ` = ` ` 1 ` ` diff ` ` = ` ` 0.5 ` ` print ` ` (create (limit, diff)) `

Exit:

``` [-1, -0.5, 0.0, 0.5, 1] ​​   Approach # 2  Using Python Numpy   Using the Numpy module makes the solution much easier. In this method we use ` np.arange ` which returns evenly spaced values ​​in a given interval & # 39; diff & # 39 ;.           ` `  ` # Python3 conversion program `  ` # list to dictionary `   ` import ` ` numpy as np `     ` def ` ` create (limit, diff): `   ` lst ` ` = ` ` np.arange (diff, limit , diff) `   ` if ` ` (lst [` ` - ` ` 1 ` `]! ` ` = ` ` limit): `  ` ` ` lst ` ` = ` ` np.r_ [lst, limit] `      ` return ` ` np.r_ [` ` - ` ` lst [:: ` ` - ` ` 1 ` `], ` ` 0 ` `, lst ] .tolist () `    ` # Driver code `   ` limit ` ` = ` ` 1 `   ` diff ` ` = ` ` 0.5 `   ` print ` ` (create (limit, diff)) `         Exit:  [-1, -0.5, 0.0, 0.5, 1] ​​