為什么我的代碼繼續？

Question

該代碼應采用用戶輸入的形狀類型。 然后輸入高度，然后打印由*組成的形狀（目前為三角形/正方形）

該代碼將一直起作用，直到用戶鍵入錯誤的輸入才能啟動，然后輸入正確的函數名稱並嘗試將其關閉。 任何想法如何解決它？

錯誤：

Enter shape to draw (q to quit): sad
Unknown shape. Please try again
Enter shape to draw (q to quit): triangle
Enter size: 6
*
**
***
****
*****
******
Enter shape to draw (q to quit): q
Goodbye
Enter size: #this should not be there

整個代碼是““”喬丹·漢普森的形狀程序“”“

def main():
    """main boss function"""
    shape = input("Enter shape to draw (q to quit): ").lower()

    if shape == "q":
        print("Goodbye")
        return



    else:
        get_valid_shape(shape)

        call_shape(shape)

        main()



def call_shape(shape):
    """CALLS THE shape"""

    size = int(input("Enter size: "))
    get_valid_size(size)
    if shape == "square":
        return print_square(size)

    elif shape == "triangle":
        return print_triangle(size)

    else: 
        return main()


def get_valid_size(size):
    """checks to see if the size is valid"""
    if size <= 0:
        print("Value must be at least 1")
        main()

def get_valid_shape(shape):
    """gets a valid shape"""
    shape_1 = shape
    shapes = ["square", "triangle", "q"]
    while shape_1 not in shapes:
        print("Unknown shape. Please try again")
        return main()


def print_square(size):
    """prints a square from the input"""
    for _ in range(0, size):
        print(size * "*")


def print_triangle(size): 
    """prints a triangle in *'s"""   
    for _ in range(1, size +1):
        print((size -(size -_)) * "*")  

main()

Answer 1

這是由於您的函數get_valid_shape（），函數調用函數fonmain（），所以當您輸入“ sad”時，您將啟動一個新的main（），但在函數get_valid_shape（）中（在主過程中，您仍然處在get_valid_shape(shape)行中） get_valid_shape(shape) ）。 當您按“ q”時，您退出此行並傳遞給call_shape(shape) ，上一個形狀是三角形，因此它要求您輸入尺寸。

為了避免這種情況，我建議使用此代碼

def main():
    shape = ""
    while shape != "q":
        """main boss function"""
        shape = "" #reinitialize 
        shape = input("Enter shape to draw (q to quit): ").lower()

        if shape == "q":
            print("Goodbye")

        elif get_valid_shape(shape) :
            call_shape(shape)

        else:
            print("Unknown shape. Please try again")



def call_shape(shape):
    """CALLS THE shape"""

    size = int(input("Enter size: "))#ask a 1st time withour print error message
    while get_valid_size(size): #while size is false, ask again
        size = int(input("Enter size: "))

    if shape == "square":
        return print_square(size)

    elif shape == "triangle":
        return print_triangle(size)



def get_valid_size(size):
    """checks to see if the size is valid"""
    if size <= 0: 
        print("Value must be at least 1")
        return True #return true to loop at the while
    else :
        return False #return false to break the while

def get_valid_shape(shape):
    """gets a valid shape"""
    shape_1 = shape
    shapes = ["square", "triangle", "q"]
    if shape_1 not in shapes:
        return False
    else :
        return True


def print_square(size):
    """prints a square from the input"""
    for _ in range(0, size):
        print(size * "*")


def print_triangle(size): 
    """prints a triangle in *'s"""   
    for _ in range(1, size +1):
        print((size -(size -_)) * "*")  

main()

我建議您使用python中的pdb模塊。 這是一個調試模塊非常有用的（你可以看到如何一步運行algorithme一步，去什么地方，到一個函數等） 鏈接

Answer 2

您以錯誤的方式使用了這些return ，您實際上並不需要任何return值，因為您在代碼中沒有做任何事情！

def main():
    """main boss function"""
    shape = input("Enter shape to draw (q to quit): ").lower()

    if shape == "q":
        print("Goodbye")

    else:
        get_valid_shape(shape)
        call_shape(shape)
        main()

def call_shape(shape):
    """CALLS THE shape"""

    size = int(input("Enter size: "))
    get_valid_size(size)
    if shape == "square":
        print_square(size)

    elif shape == "triangle":
        print_triangle(size)

    else: 
        main()

def get_valid_size(size):
    """checks to see if the size is valid"""
    if size <= 0:
        print("Value must be at least 1")
        main()

def get_valid_shape(shape):
    """gets a valid shape"""
    while shape not in ["square", "triangle", "q"]:
        print("Unknown shape. Please try again")
        main()


def print_square(size):
    """prints a square from the input"""
    for _ in range(0, size):
        print(size * "*")


def print_triangle(size): 
    """prints a triangle in *'s"""   
    for _ in range(1, size +1):
        print((size -(size -_)) * "*")  

main()

在我看來，這是一個糟糕的代碼，因為您使用了無用的函數，而無需使用它們就可以編寫整個代碼。

inProgram = True
while inProgram:
    shape = raw_input("Enter shape to draw (q to quit): ").lower()
    while shape not in ["square", "triangle", "q"]:
        shape = raw_input("Unknown shape. Please try again: ").lower()
    if shape == "q":
        print("Goodbye")
        inProgram=False
    else:
        size = raw_input("Enter size: ")
        while not size.isdigit() or size<=0:
            size = raw_input("Value must be at least 1\nTry again: ")
        size = int(size)
        if shape == "square":
            for _ in range(0, size):
                print(size * "*")
        else:
            for _ in range(1, size +1):
                print((size -(size -_)) * "*")