# Copysign() Function - Python Math Module

## Overview:

• The function copysign() from the math module, when passed a magnitude(m) and a number(ss) as a sign source, the function copies the sign from ss to m
• Python does not have a sign() function. Simulating sign() function using copysign() is possible in two ways:
• Give a negative number as ss and 1 as m to copysign(), which will return -1.
• Give a positive number as ss and 1 as m to copysign(), which will return 1.

## Example 1:

 # Example program that copies a sign from another number # for a given number and returns a float import math # Copy the sign of a positive number to a negative number v = math.copysign(-4, 3) print(v) # Copy the sign of a negative number to a positive number v = math.copysign(4, -3) print(v) # Copy the sign of a negative number to a negative number v = math.copysign(-4.1, -4) print(v) print(type(v))

## Output:

 4.0 -4.0 -4.1

## Example 2:

 # Example Python program simulating sign function import math # Sign(negative quantity) magnitude   = 1 signSource  = -4 value = math.copysign(magnitude, signSource) print(value) # Sign(postive quantity) magnitude   = 1 signSource  = 4 value = math.copysign(magnitude, signSource) print(value)

## Output:

 -1.0 1.0