回文，Python，问题

如何解决回文，Python，问题

我是 Python 编程新手，只是为了好玩而学习。我想知道为什么这个程序很难输出正确的输出。我相信问题出在程序的最后“if list == inverselist:”。 我总是得到一个输出，告诉我这个词是回文，即使它不是（例如老虎）

#Exercise 6 - Ask the user for a string and print out whether this string is a palindrome or not. (A palindrome is a string that reads the same forwards and backwards.)

possiblepalindrome = str(input("Put in the possible palindromic statement here: "))
print(possiblepalindrome)
list=[]

for x in possiblepalindrome: #put each individual string character in a new list as its own element
    list.append(x)
print ('this is list',list)

for x in list: #Removes all spaces so multiple word/sentences can be palindrome
    if x is ' ':
        list.remove(' ')
print('this is with removed spaces',list) 


def reverselist(argument): #This is a function. We put in some list,then the list is reversed,and is spat back out
    argument.reverse()
    return argument

inverselist = reverselist(list) #We use the reverselist function to make an inverse list of the palindrome
print('this is inverselist',inverselist)


if list == inverselist:
    print('Congratulations ','"',possiblepalindrome,' is a palindrome!')
else:
    print('Unfortunately','is not a palindrome.')

解决方法

list 和 inverselist 具有对同一个列表的引用。您需要克隆 list。

只需更改 reverselist 函数

def reverselist(argument): #This is a function. We put in some list,then the list is reversed,and is spat back out
    li_copy = [] 
    li_copy.extend(argument)
    li_copy.reverse()
    return li_copy

完整代码：

possiblepalindrome = str(input("Put in the possible palindromic statement here: "))
print(possiblepalindrome)
list=[]

for x in possiblepalindrome: #put each individual string character in a new list as its own element
    list.append(x)
print ('this is list',list)

for x in list: #Removes all spaces so multiple word/sentences can be palindrome
    if x is ' ':
        list.remove(' ')
print('this is with removed spaces',list) 


def reverselist(argument): #This is a function. We put in some list,and is spat back out
    li_copy = [] 
    li_copy.extend(argument)
    li_copy.reverse()
    return li_copy

inverselist = reverselist(list) #We use the reverselist function to make an inverse list of the palindrome
print('this is inverselist',inverselist)


if list == inverselist:
    print('Congratulations ','"',possiblepalindrome,' is a palindrome!')
else:
    print('Unfortunately','is not a palindrome.')

,

您发布了太多代码，却懒得去测试。 = 不符合您的预期。它反转输入列表，这是一个可变对象。

reverselist

输出：

def reverselist(argument): #This is a function. We put in some list,and is spat back out
    argument.reverse()
    return argument

word = list("Hello,world")
print(word)
inverseword = reverselist(word)
print(word,'\n',inverseword)

简而言之，您颠倒了列表，然后将结果与其自身进行了比较。

注意事项：

• 不要不要使用预定义的名称作为变量。我将 ['H','e','l','o',',' ','w','r','d'] ['d','H'] ['d','H'] 更改为 list。
• 查找如何反转序列。我们希望您在此处发帖之前进行适当的研究。
• 学习测试代码块。请参阅 debugging help 的这个可爱参考。

您的功能可以很简单：

word

,

首先，将列表命名为 list 很诱人，但在 Python 中很危险，因为您将无法调用 list() 构造函数

基本上你的代码可以这样减少

possiblepalindrome = str(input("Put in the possible palindromic statement here: "))
print(possiblepalindrome)

normal_list = list(possiblepalindrome.remove(" "))
inverselist= list(reversed(possiblepalindrome))
print('this is inverselist',"".join(inverselist))

if list == inverselist:
    print('Congratulations ','is not a palindrome.')

,

要检查一个字符串是否是回文：

v = str(input("Put in the possible palindromic statement here: "))

print (v == (v[::-1]))

只需输入，与相反的比较。如果它们相等，你会得到一个 True（所以它是一个回文），否则得到一个 False。