如果,elif没有按预期工作

Question

我是Python的新手,我不知道为什么,但是if,elif在下面的代码中,我没有按照预期的那样工作.然而,

• 当我输入1到7时它完美地工作

• 当我输入0 8或9时它完美地工作(它说"再试一次")

• 如果我输入10到69,100到任何数字,它不起作用

当我说它不起作用我的意思是打印

my_shape_num = h_m.how_many()

但我不知道为什么.如果选择不在1到7之间,它必须停止

def main(): # Display the main menu
    while True:
        print
        print "  Draw a Shape"
        print "  ============"
        print
        print "  1 - Draw a triangle"
        print "  2 - Draw a square"
        print "  3 - Draw a rectangle"
        print "  4 - Draw a pentagon"
        print "  5 - Draw a hexagon"
        print "  6 - Draw an octagon"
        print "  7 - Draw a circle"
        print
        print "  X - Exit"
        print

        choice = raw_input('  Enter your choice: ')

        if (choice == 'x') or (choice == 'X'):
            break

        elif (choice >= '1' and choice <= '7'):
            my_shape_num = h_m.how_many()
            if ( my_shape_num is None): 
                continue

            d_s.start_point() # start point on screen

            if choice == '1': 
                d_s.draw_triangle(my_shape_num) 
            elif choice == '2': 
                d_s.draw_square(my_shape_num) 
            elif choice == '3':             
                d_s.draw_rectangle(my_shape_num) 
            elif choice == '4':             
                d_s.draw_pentagon(my_shape_num) 
            elif choice == '5':             
                d_s.draw_hexagon(my_shape_num) 
            elif choice == '6':             
                d_s.draw_octagon(my_shape_num) 
            elif choice == '7': 
                d_s.draw_circle(my_shape_num)

        else:
            print
            print '  Try again'
            print

---

编辑:好的,排序:

choice = raw_input('  Enter your choice: ')

if (choice == 'x') or (choice == 'X'):
    break


try:
    choice = int(choice)
    if (1 <= choice <= 7):

        my_shape_num = h_m.how_many()
        if ( my_shape_num is None): 
            continue

        d_s.start_point() # start point on screen

        if choice == 1: 
            d_s.draw_triangle(my_shape_num) 
        elif choice == 2: 
            d_s.draw_square(my_shape_num) 
        elif choice == 3:             
            d_s.draw_rectangle(my_shape_num) 
        elif choice == 4:             
            d_s.draw_pentagon(my_shape_num) 
        elif choice == 5:             
            d_s.draw_hexagon(my_shape_num) 
        elif choice == 6:             
            d_s.draw_octagon(my_shape_num) 
        elif choice == 7: 
            d_s.draw_circle(my_shape_num)

    else:
        print
        print '  Number must be from 1 to 7!'
        print

except ValueError:
    print
    print '  Try again'
    print

Answer 1

字符串按字典顺序进行比较:'10'大于'1'但小于'7'.现在考虑这段代码:

elif (choice >= '1' and choice <= '7'):

除了接受'7',这将接受任何字符串开头1,2,3,4,5或6.

要修复,choice请在测试后立即转换为整数'x',然后使用整数比较.