用 python 测量从英尺和英寸到米和厘米答案

【问题标题】：measurement with python from foot and inch to meter and centimeter用 python 测量从英尺和英寸到米和厘米
【发布时间】：2021-06-01 11:18:43
【问题描述】：

大家好，我想制作一个反转测量的程序首先，用户输入两个或三个数字，反转将是米和厘米，但它没有显示正确的答案，唯一的答案是 0 我会如果你能帮助我，非常感谢

foot = inch = 0


foot_to_meter = foot_to_centimeter = inch_to_meter = inch_to_centimeter =0
def read():
    foot = int(input('foot?'))
    inch = int(input('inch?'))
def calculater():
    foot_to_meter = 0.3048 * foot
    foot_to_centimeter = 100 * foot_to_meter
    # inch_to_meter = 12  * foot
    inch_to_meter = (1.0/12) * 0.3048* inch
    inch_to_centimeter = 100 * inch_to_meter
def write():
    print(f'foot is  {foot_to_centimeter} centimeter and {foot_to_meter} meter')
    print(f'inch is  {inch_to_centimeter} centimeter and {inch_to_centimeter} meter')
    # print('the' foot 'is' meter 'meter' 'and' 'foot is' foot_to_centimeter)
    # print('the' inch 'is' meter 'meter' "and" 'icnh is' inch_to_centimeter )

def main():
    read()
    calculater()
    write()

main()

【问题讨论】：

标签： measure measurement

【解决方案1】：

如果您在 python 中为变量赋值，它不会自动使用global 作用域变量，而是将它们分配给局部作用域变量。请注意，对于只读函数，global 会自动使用变量。

要解决您的问题，您可以在分配给全局变量之前使用 global 关键字。

foot = inch = 0
foot_to_meter = foot_to_centimeter = inch_to_meter = inch_to_centimeter =0
def read():
    global foot, inch
    foot = int(input('foot?'))
    inch = int(input('inch?'))
def calculater():
    global foot_to_meter, foot_to_centimeter, inch_to_meter, inch_to_centimeter
    foot_to_meter = 0.3048 * foot
    foot_to_centimeter = 100 * foot_to_meter
    # inch_to_meter = 12  * foot
    inch_to_meter = (1.0/12) * 0.3048* inch
    inch_to_centimeter = 100 * inch_to_meter
def write():
    print(f'foot is  {foot_to_centimeter} centimeter and {foot_to_meter} meter')
    print(f'inch is  {inch_to_centimeter} centimeter and {inch_to_centimeter} meter')
    # print('the' foot 'is' meter 'meter' 'and' 'foot is' foot_to_centimeter)
    # print('the' inch 'is' meter 'meter' "and" 'icnh is' inch_to_centimeter )

def main():
    read()
    calculater()
    write()

main()

我想指出，在处理更大的代码库和导入模块时，全局变量通常会导致麻烦，这就是为什么我建议在非绝对必要时不要使用它们的原因。你可以像这样重写你的程序：

def read():
    foot = int(input('foot?'))
    inch = int(input('inch?'))
    return foot, inch
def calculater(foot, inch):
    foot_to_meter = 0.3048 * foot
    foot_to_centimeter = 100 * foot_to_meter
    # inch_to_meter = 12  * foot
    inch_to_meter = (1.0/12) * 0.3048* inch
    inch_to_centimeter = 100 * inch_to_meter
    return foot_to_meter, foot_to_centimeter, inch_to_meter, inch_to_centimeter
def write(foot_to_meter, foot_to_centimeter, inch_to_meter, inch_to_centimeter):
    print(f'foot is  {foot_to_centimeter} centimeter and {foot_to_meter} meter')
    print(f'inch is  {inch_to_centimeter} centimeter and {inch_to_centimeter} meter')
    # print('the' foot 'is' meter 'meter' 'and' 'foot is' foot_to_centimeter)
    # print('the' inch 'is' meter 'meter' "and" 'icnh is' inch_to_centimeter )

def main():
    foot, inch = read()
    foot_to_meter, foot_to_centimeter, inch_to_meter, inch_to_centimeter = calculater(foot, inch)
    write(foot_to_meter, foot_to_centimeter, inch_to_meter, inch_to_centimeter)

main()

【讨论】：