我的Python 3.x程序有什麼問題？

Question

我寫的所有的Python中的數學函數，但是當用戶

print ("""Calculations Menu: 
    1) Area (Square) 
    2) Area (Rectangle) 
    3) Area (Circle) 
    4) Perimeter (Square) 
    5) Perimeter (Rectangle) 
    6) Perimeter (Circle) 
    7) Exit 
""") 

choice = input("Input Menu Choice (1,2,3,4,5,6 or 7)?\n") 

if choice == "1": 
    print ("You have chosen Area (Square)") 

    def area_square (width, height): 
     return width * height 

    def positive_input (prompt): 
     number = float(input(prompt)) 
     while number <=0: 
      print ("Must be a positive number.") 
      number = float(input(prompt)) 
     return number 

    w = positive_input ("Width: ") 
    h = positive_input ("Height: ") 

    print ("Width = ", w, "Height = ", h, "So Area =", area_square(w, h)) 

if choice == "2": 
    print ("You have chosen Area (Rectangle)") 

    def area_rectangle (width, height): 
     return width * height 

    def positive_input (prompt): 
     number = float(input(prompt)) 
     while number <=0: 
      print ("Must be a positive number.") 
      number = float(input(prompt)) 
     return number 

    w = positive_input ("Width: ") 
    h = positive_input ("Height: ") 

    print ("Width = ", w, "Height = ", h, "So Area =", area_rectangle(w, h)) 

if choice == "3": 
    print ("You have chosen Area (Circle)") 

    def area_circle (radius, pi): 
     return radius**2 * pi 

    def positive_input (prompt): 
     number = float(input(prompt)) 
     while number <=0: 
      print ("Must be a positive number.") 
      number = float(input(prompt)) 
     return number 

    radius = positive_input ("radius: ") 
    pi = 3.14159265 

    print ("Radius = ", radius, "Pi = ", pi, "So Area =", area_circle(radius, pi)) 

if choice == "4": 
    print ("You have chosen Perimeter (Square)") 

    def perimeter_square (side,): 
     return side * 4 

    def positive_input (prompt): 
     number = float(input(prompt)) 
     while number <=0: 
      print ("Must be a positive number.") 
      number = float(input(prompt)) 
     return number 

    side = positive_input ("side: ") 

    print ("side = ", "So Perimeter =", perimeter_square(side,)) 

if choice == "5": 
    print ("You have chosen Perimeter (Rectangle)") 

    def perimeter_rectangle (sideA, sideB,): 
     return (sideA + sideB) * 2 

    def positive_input (prompt): 
     number = float(input(prompt)) 
     while number <=0: 
      print ("Must be a positive number.") 
      number = float(input(prompt)) 
     return number 

    sideA = positive_input ("Length: ") 
    sideB = positive_input ("Width: ") 

    print ("Length = ", sideA, "Width = ", sideB, "So Perimeter =", perimeter_rectangle(sideA, sideB)) 

if choice == "6": 
    print ("You have chosen Perimeter (Circle)") 

    def perimeter_circle (diameter, pi): 
     return diameter * pi 

    def positive_input (prompt): 
     number = float(input(prompt)) 
     while number <=0: 
      print ("Must be a positive number.") 
      number = float(input(prompt)) 
     return number 

    diameter = positive_input ("Diameter: ") 
    pi = 3.14159265 

    print ("Diameter = ", diameter, "Pi = ", pi, "So Perimeter =", perimeter_circle(diameter, pi)) 

Answer 1

提示這或許會投你的問題的一些光不能讓程序去正確的選項：

In [6]: choice = input("Input Menu Choice (1,2,3,4,5,6 or 7)?\n") 
Input Menu Choice (1,2,3,4,5,6 or 7)? 
1 

In [7]: type(choice) 
Out[7]: int 

In [9]: choice == "1" 
Out[9]: False 

In [10]: choice == 1 
Out[10]: True 

Answer 2

當我運行你的代碼時，它工作得很好，當然除了它通過所有7種可能性，而不僅僅是你選擇的。 （請注意，如果您使用Python 2.x解釋器而不是3.x來運行此代碼，它將顯示工作，但從不執行任何操作。這是因爲在2.x中，input將評估其輸入，因此choice將是，例如，int 3，而不是字符串"3"。但是，如果您按照預期使用Python 3解釋器運行它，這不是問題。）

它這樣做的原因只是縮進。你已經得到了只能運行給定選擇的代碼，但它並沒有在正確的if區塊下縮進。一旦你解決了，一切都很好。

由於定義完全相同的positive_input函數6次是愚蠢的，所以我將該部分移到頂端。否則，我做出的唯一改變是縮進：

def positive_input (prompt): 
    number = float(input(prompt)) 
    while number <=0: 
     print ("Must be a positive number.") 
     number = float(input(prompt)) 
    return number 

print ("""Calculations Menu: 
    1) Area (Square) 
    2) Area (Rectangle) 
    3) Area (Circle) 
    4) Perimeter (Square) 
    5) Perimeter (Rectangle) 
    6) Perimeter (Circle) 
    7) Exit 
    """) 

choice = input("Input Menu Choice (1,2,3,4,5,6 or 7)?\n") 

if choice == "1": 
    print ("You have chosen Area (Square)") 

    def area_square (width, height): 
     return width * height 

    w = positive_input ("Width: ") 
    h = positive_input ("Height: ") 

    print ("Width = ", w, "Height = ", h, "So Area =", area_square(w, h)) 

if choice == "2": 
    print ("You have chosen Area (Rectangle)") 

    def area_rectangle (width, height): 
     return width * height 

    w = positive_input ("Width: ") 
    h = positive_input ("Height: ") 

    print ("Width = ", w, "Height = ", h, "So Area =", area_rectangle(w, h)) 

if choice == "3": 
    print ("You have chosen Area (Circle)") 

    def area_circle (radius, pi): 
     return radius**2 * pi 

    radius = positive_input ("radius: ") 
    pi = 3.14159265 

    print ("Radius = ", radius, "Pi = ", pi, "So Area =", area_circle(radius, pi)) 

if choice == "4": 
    print ("You have chosen Perimeter (Square)") 

    def perimeter_square (side,): 
     return side * 4 

    side = positive_input ("side: ") 

    print ("side = ", "So Perimeter =", perimeter_square(side,)) 

if choice == "5": 
    print ("You have chosen Perimeter (Rectangle)") 

    def perimeter_rectangle (sideA, sideB,): 
     return (sideA + sideB) * 2 

    sideA = positive_input ("Length: ") 
    sideB = positive_input ("Width: ") 

    print ("Length = ", sideA, "Width = ", sideB, "So Perimeter =", perimeter_rectangle(sideA, sideB)) 

if choice == "6": 
    print ("You have chosen Perimeter (Circle)") 

    def perimeter_circle (diameter, pi): 
     return diameter * pi 

    diameter = positive_input ("Diameter: ") 
    pi = 3.14159265 

    print ("Diameter = ", diameter, "Pi = ", pi, "So Perimeter =", perimeter_circle(diameter, pi)) 

---

雖然我們在這，其他一些改變我可能會做（主要是未成年人）：

首先，Python style強烈反對在函數調用的括號之前放置空格。

接下來，你可以使用math.pi獲得pi向右精度爲您的Python構建的float類型，而不必輸入自己逼近，並在精密猜測。

如果您將一串互斥的語句鏈接在一起，則使用elif會向讀者明確指出它們應該是互斥的。

你可能要考慮越走越每個選擇進入一個功能，所以你可以這樣做：

if choice == "1": 
    do_area_square() 
elif choice == "2": 
    do_area_rectangle() 
# ... 

...甚至：

functions = {"1": do_area_square, "2": do_area_rectangle, # ... 
functions[choice]() 

...或：

functions = [do_area_square, do_area_rectangle, ...] 
functions[int(choice)-1]()