how to make a negative number positive in python

1a = abs(-1)
2return a
3
4#returns 1

1>>> n = -42
2>>> -n       # if you know n is negative
342
4>>> abs(n)   # for any n
542
6>>> abs(-5.05)
75.05

1a = -abs(a)

1number_to_check = input("enter a number: ")
2
3try:
4    if number_to_check < 0:
5        print("That number is a negative number")
6    else:
7        print("That number is not a negative number")
8
9# Error handling, in case input was a string
10except TypeError:
11    print("That wasn't a number")

1x = abs(x)