数值的整数次方--python

def Power(num,exponent):
    if num > -1e-7 and num < 1e-7:
    	return 0
    if exponent == 0:
    	return 1
    ex1 = abs(exponent)
    result = 1.0
    for i in range(ex1):
    	result *= num
    if exponent > 0:
        return result
    else:
        return 1/result
# print(Power(2,-2))