python 正数变负数

num = 5
negative_num = -num
print(negative_num)  # 输出: -5

num = 5
negative_num = num * -1
print(negative_num)  # 输出: -5

def make_negative(num):
    return -abs(num)

num = 5
negative_num = make_negative(num)
print(negative_num)  # 输出: -5

value = "5"
negative_value = -value  # 这将引发 TypeError

value = "5"
if isinstance(value, (int, float)):
    negative_value = -value
else:
    try:
        negative_value = -float(value)
    except ValueError:
        print("输入不是一个有效的数字")

num = 0.1
negative_num = -num
print(negative_num)  # 输出可能不是精确的 -0.1

from decimal import Decimal

num = Decimal('0.1')
negative_num = -num
print(negative_num)  # 输出: -0.1