Percentage Change

percentage_change.py

from decimal import Decimal

def percentage_change(old_value, new_value):
    """
    Accepts two integers, an old and a new number, 
    and then measures the percent change between them.
    """
    change = abs(new_value - old_value)
    try:
        pct_change = (change / Decimal(old_value))
        return pct_change*100
    except ZeroDivisionError:
        return None