Question

在编程中，我正在编写一个用户选择实体的代码，然后计算体积和表面积。但是我没有直接选择，而是向用户提供了询问有关实体的额外信息的选项，如果他们输入数字然后“显示”（例如'1 show'）。他们可以继续询问，直到选择了一个实体，所以我使用了一个while循环。

循环不起作用。如果循环的条件无效，它仍会进入循环并且不让我离开。请帮忙。我觉得这很简单。我试图进行整数和字符串转换，没有它帮助。

#11/07/12 
#A program that asks user for input and calculates SA and Volume of a chosen solid

print "Which solid would you like to calculate?"    
print "  "      
print "1. Tetrahedron"          
print "2. Dodecahedron"           
print "3. Cone"                 
print "4. Sphere"                        
print "5. Icosahedron"                    
print '  '                        
print "If you want extra information on the solid, enter the solid's number and then add show. Example: 1 show"                   
print "If not, just enter the number"                       
choice = raw_input('----->')                             

#Where asks if user wants extra information on the solids, loops until solid is chosen             
while choice != '1' or choice != '2' or choice != '3' or choice != '4' or choice != '5':      
    if choice == "1 show":     
        print "A tetrahedron is composed of four congruent triangle faces. "     
    if choice =='2 show':      
        print "A dodecahedron is a polyhedron composed of 12 pentagonal faces. "      
    if choice == '3 show':       
        print 'A cone is a geometric solid that tapers smoothly from a circular base to an   apex. '          
    if choice == '4 show':          
        print "A sphere is a perfectly round circle. "            
    if choice == '5 show':
        print 'An icosahedron is a regular polyhedron with 20 congruent equilateral triangular faces'        
    choice = raw_input('Your new choice: ')              

if choice == 1: # Tetradedron               
    tetraside = raw_input("What is the length of your solid's side? ")               
    tetrabaseA = ((3 ** (1/2)) / 4) * tetraside**2                
    tetraheight = 9 * ((6 ** (1/2)) / 3) * tetraside                  
    tetraSA = 4 * tetrabaseA                
    tetraV = (1 / 3) * tetrabaseA * tetraheight

Answer 1

您的while条件错误。想一想：即使choice等于'1'，条件choice != '2'也将成立，因此整个条件将始终得到满足。

你需要像

这样的东西

while choice not in {'1', '2', ...}:

或

while choice not in set(map(str, range(1, 6))): # a fancier version

或只是将您的所有or更改为and。

Answer 2

请注意，虽然您的错误是在循环条件下，但是您可以通过使用字典查找而不是大if elif else块来使您的其他一些代码更加“Pythonic”。

例如，你的while循环可以简化为：

info = { "1 show" : "A tetrahedron is composed of four congruent triangle faces.",
         "2 show" : "A dodecahedron is a polyhedron composed of 12 pentagonal faces.",
         "3 show" : "A cone is a geometric solid that tapers smoothly from a circular base to an   apex.",
         "4 show" : "A sphere is a perfectly round circle.",
         "5 show" : "An icosahedron is a regular polyhedron with 20 congruent equilateral triangular faces" }

while choice not in { "1", "2", "3", "4", "5" }:
    print info.get(choice, "I'm sorry, I didn't understand your input.")
    choice = raw_input('Your new choice: ')

您可以稍后执行类似于体积和表面区域的实际计算，但您可能需要将这些计算的代码放入单独的函数中，然后将函数放入字典（甚至是列表，因为索引将是整数）。

简单的python代码

2 个答案: