Python | The opposite sign of each item in the given list

Examples :

  Input:  [-1, 2, 3, -4, 5, -6, -7]  Output:  [1, -2, -3, 4, -5, 6, 7]  Input:  [-5, 9, -23, -2, 7]  Output:  [5, -9, 23, 2, -7] 

Methods # 1: List comprehension

# Python3 program for converting positives
# list of integers to negative and vice versa

def Convert (lst):

return [ - i for i in lst]

 
# Driver code

lst = [ - 1 , 2 , 3 , - 4 , 5 , - 6 , - 7 ]

print (Convert (lst))

Exit:

 [1, -2, -3, 4, -5, 6, 7] 

Methods # 2: Using NumPy
It is also possible to use the Python Numpy module which is the most pythonic way to solve this problem. The list is first converted to a numpy array, and then the negative element of the array is returned, which is eventually converted to a list.

# Python3 positive conversion program
# list of integers to negative and vice versa

import numpy as np

 

def Convert (lst):

lst = np.array (lst)

return list ( - lst)

  
# Driver code

lst = [ - 1 , 2 , 3 , - 4 , 5 , - 6 , - 7 ]

print (Convert (lst))

Exit:

 [1, -2, -3, 4, -5 , 6, 7]