如何使另一个函数中的变量在另一个Python上工作？

Question

所以这是我的整个代码，当我说window_Calculate()没有定义高度时，我遇到了麻烦。 我的目标是使用公式50 + (height * width) * 100 。 在window_Size ，用户必须输入height和width但是如果他们键入不是数字的任何内容，则应该返回该height和width ，以便他们可以输入实际数字。 总体而言，在其他功能中未定义height ，并且如果用户输入数字以外的任何内容， height都不会返回到输入。 如何定义height并返回输入？

import time 

def Intro():
    print("Welcome to Wendy's Windows.")
    time.sleep(2)
    print("This is a window replacement business.")
    time.sleep(2)
    print("Enter your size in the box on the left and the price will be displayed below.")
    time.sleep(2.5)

def window_Size():
    print("Put height first then put width.")
    time.sleep(1.5)
    height = input("Height: ")
    try:
        int(height)
    except ValueError:
         try:
            float(height)
         except ValueError:
            print("Enter only numbers.")
            return(height)
    else:
        print(height + "m")
    width = input("Width: ")
    try:
        int(width)
    except ValueError:
        try:
            float(width)
        except ValueError:
                print("Enter only numbers.")
                return(width)
    else:
        print(width + "m")

def window_Calculate():
    window_Calculate = '50' + (height * width) * '100'

def window_Cost():
    print("Your price is" + window_Calculate + "$")

window_Size()
window_Calculate()
window_Cost()

Answer 1

因此，这里有几件事：

1. window_Size()的try/except类型测试
2. window_Size()调用return(height)但不存储它
3. 使用非局部变量但没有给定参数的window_Calculate()

您正在尝试使用的是所谓的global variable 。 在几乎任何编程语言中，都不鼓励使用它们。 相反，你应该使用一个local variable被称为函数内作用域return可变后向上级调用函数。

下面，我指出了您程序中的一些亮点，并给出了更改后的程序再现。 虽然是一种解决方案，但我不了解您对这些概念有多少了解，因此对您的程序进行一点点修改即可清楚地说明要点。 但是，可以对其进行显着更改，使其更加Python化和完善。

1号：

def window_Size():
    print("Put height first then put width.")
    time.sleep(1.5) # bit annoying to sleep all the time?
    height = input("Height: ")
    try:
        int(height) # type test of int, that's fine
    except ValueError: # correct catch
         try:
            float(height) # type test of float, that's fine
         except ValueError: # correct catch; must be invalid
            print("Enter only numbers.") # message for user
            return(height) # wait why did you return??
    else: # wont be executed if above return() is called (i.e. for str())
        print(height + "m")
    width = input("Width: ")
    try:
        int(width)
    except ValueError:
        try:
            float(width)
        except ValueError:
                print("Enter only numbers.")
                return(width) # All the same notes above apply
    else:
        print(width + "m")

因此，您使用的try/except/else很好，但是在单个函数中有2个return()调用； 一被调用， window_Size()将立即退出（即，如果调用return(height)则不width 。此外，要返回多个值，可以使用tuple 。

2号：

window_Size() # this functions returns values, but isnt storing

3号

window_Calculate() # this functions uses returns values, but isnt passed any

解：

import time 

def intro():
    print("Welcome to Wendy's Windows.")
    time.sleep(2) # personally I'd get rid of all time.sleep() calls
    print("This is a window replacement business.")
    time.sleep(2)
    print("Enter your size in the box on the left and the price will be displayed below.")
    time.sleep(2.5)
    process_customer()

def process_customer():
    size = window_size()
    # get rid of window_calculate() all together
    total = window_cost(size)
    print("Your price is" + str(total) + "$")

def window_size():
    print("Put height first then put width.")
    while True:
        height = input("Height: ")
        try:
            h = int(height)
            break
        except ValueError:
             try:
                h = float(height)
                break
             except ValueError:
                print("Enter only numbers.")
    print(height + "m")
    while True:
        width = input("Width: ")
        try:
            w = int(width)
            break
        except ValueError:
            try:
                w = float(width)
                break
            except ValueError:
                print("Enter only numbers.")
    print(width + "m")
    return h, w

def window_cost(size):
    return 50 + (size[0] + size[1]) * 100 # before 50 and 100 were str()

intro()

Answer 2

您应该确保height，width和window_Calculate是全局变量，以便可以在A函数中更改它们，并在B函数中使用它们。

Answer 3

pstatix的答案是最好的解决方案，应该接受

您需要每个方法都可以获取或设置“全局”变量。 尝试这个：

import time 

window_height = 0
window_width = 0
window_value = 0

def Intro():
    print("Welcome to Wendy's Windows.")
    time.sleep(2)
    print("This is a window replacement business.")
    time.sleep(2)
    print("Enter your size in the box on the left and the price will be displayed below.")
    time.sleep(2.5)

def window_Size():
    global window_height
    global window_width
    print("Put height first then put width.")
    time.sleep(1.5)
    height = input("Height: ")
    try:
        int(height)
    except ValueError:
         try:
            float(height)
         except ValueError:
            print("Enter only numbers.")
            return(height)
    else:
        print(str(height) + "m")
        window_height = height
    width = input("Width: ")
    try:
        int(width)
    except ValueError:
        try:
            float(width)
        except ValueError:
                print("Enter only numbers.")
                return(width)
    else:
        print(str(width) + "m")
        window_width = width

def window_Calculate():
    global window_value
    window_value = 50 + window_height * window_width * 100

def window_Cost():
    print("Your price is $" + str(window_value))











window_Size()
window_Calculate()
window_Cost()