Python:未定义变量，不确定如何在不同的def上携带变量

Question

我正在尝试使用另一个函数中的变量，但我不知道如何访问它。如果有必要的话，我不知道把global放在哪里。

以下是我目前所拥有的：

#Defs
def getAngle1():
    angle1 = eval(input("Please enter the first angle: "))
    return angle1
def getAngle2():
    angle2 = eval(input("Please enter the second angle: "))
    return angle2
def getAngle3():
    angle3 = eval(input("Please enter the third angle: "))
    return angle3
def main():
    getAngle1()
    getAngle2()
    getAngle3()
    if angle1 == 90:
        print ("This is a right triangle!")
    elif angle2 == 90:
        print ("This is a right triangle!")
    elif angle3 == 90:
        print ("This is a right triangle!")
    else:
        print ("This is not a right triangle.")
#Driver
main()

我得到这个错误：

Traceback (most recent call last):
  File "C:/Documents and Settings/user1/My Documents/AZ_isitRightRevised.py", line 29, in <module>
    main()
  File "C:/Documents and Settings/user1/My Documents/AZ_isitRightRevised.py", line 20, in main
    if angle1 == 90:
NameError: name 'angle1' is not defined

Answer 1

问题是getAngles代码块在return angle1之后停止执行。此外，只需调用getAngles()，就不会将此函数返回的值存储在任何位置。

首先，让我们将getAngles重写为：

def getAngles():
    a1 = int(input("Please enter the first angle:"))
    a2 = int(input("Please enter the second angle:"))
    a3 = int(input("Please enter the third angle:"))
    return (a1, a2, a3)

现在，在main中，您可以执行以下操作：

def main():
    angles = getAngles()
    # rest of your code
    # angles[0] is the first angle
    # angles[1] is the second angle
    # angles[2] is the third angle

现在，您可以访问所有三个角度。你可以做的是：

if 90 in angles:    # if it's a right triangle
    print("This is a right triangle!")
else:                  # otherwise...
    print("This is not a right triangle.")