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Question

第4章末尾的“自动化镗孔”一书中的原始问题

逗号代码[用Python 3.x编写]

假设你有一个像这样的列表值：
spam = ['apples', 'bananas', 'tofu', 'cats']
编写一个以列表值作为参数并返回a的函数包含逗号和空格的所有项目的字符串，'and' 在最后一项之前插入。例如，传递前一个该函数的spam列表将返回'apples, bananas, tofu, and cats'。但是您的函数应该能够使用任何列表值传递给它。

我的问题是：
我希望修改用Python 3.x编写的结果代码，以便在命令提示符下输入一个列表，例如：1, 2, 3, 4, 5并将程序放出1, 2, 3, 4 and 5我已完成此部分的操作将从我的（很长）代码中看到。当我有一个数字和名称或单词列表并且想要这个结果时，问题出现了，我在命令提示符下键入：1, 2, 3, 4, jeremy, anna并想要以下输出：1, 2, 3, 4, jeremy and anna 正如您将从我的代码中看到的那样，我遗漏了字母表的其余部分，只是为了找到解决方案而保持简短。我试图解决这个问题的方法是使用正则表达式函数，如搜索等，并在输出中搜索逗号，逻辑是获取这些逗号的位置，然后用'and'字符串替换最后一个逗号。但我找不到任何可以实现的目标。

P.S。我的代码（下面）使用了Stack Overflow上的某个人给出的原始逗号代码问题的答案，请参阅here

#! python3.
#import re
my_input = list(input('Please enter a list of words and or numbers separated by commas:\n'))

def commacode(listname):  

 #if the last entry is equal to a number between 0 and 9 put an "and" before it then print the modified input to screen       
    if listname[len(listname) - 1] == '0':

        listname[len(listname) - 1] = 'and ' + listname[len(listname) -1]
        index = 0  
        new_string = listname[index]  
        while index < len(listname)-1:
            new_string = new_string + listname[index + 1]

            index = index + 1
            if index == len(listname)-1:
                print('\n') 
                print(new_string)

    elif listname[len(listname) - 1] == '1':
        listname[len(listname) - 1] = 'and ' + listname[len(listname) -1]
        index = 0  
        new_string = listname[index]  
        while index < len(listname)-1:
            new_string = new_string + listname[index + 1]

            index = index + 1
            if index == len(listname)-1:
                print('\n') 
                print(new_string)

    elif listname[len(listname) - 1] == '2':
        listname[len(listname) - 1] = 'and ' + listname[len(listname) -1]
        index = 0  
        new_string = listname[index]  
        while index < len(listname)-1:
            new_string = new_string + listname[index + 1]

            index = index + 1
            if index == len(listname)-1:
                print('\n') 
                print(new_string)

    elif listname[len(listname) - 1] == '3':
        listname[len(listname) - 1] = 'and ' + listname[len(listname) -1]
        index = 0  
        new_string = listname[index]  
        while index < len(listname)-1:
            new_string = new_string + listname[index + 1]

            index = index + 1
            if index == len(listname)-1:
                print('\n') 
                print(new_string)            

    elif listname[len(listname) - 1] == '4':
        listname[len(listname) - 1] = 'and ' + listname[len(listname) -1]
        index = 0  
        new_string = listname[index]  
        while index < len(listname)-1:
            new_string = new_string + listname[index + 1]

            index = index + 1
            if index == len(listname)-1:
                print('\n') 
                print(new_string)         

    elif listname[len(listname) - 1] == '5':
        listname[len(listname) - 1] = 'and ' + listname[len(listname) -1]
        index = 0  
        new_string = listname[index]  
        while index < len(listname)-1:
            new_string = new_string + listname[index + 1]

            index = index + 1
            if index == len(listname)-1:
                print('\n') 
                print(new_string)

    elif listname[len(listname) - 1] == '6':
        listname[len(listname) - 1] = 'and ' + listname[len(listname) -1]
        index = 0  
        new_string = listname[index]  
        while index < len(listname)-1:
            new_string = new_string + listname[index + 1]

            index = index + 1
            if index == len(listname)-1:
                print('\n') 
                print(new_string)

    elif listname[len(listname) - 1] == '7':
        listname[len(listname) - 1] = 'and ' + listname[len(listname) -1]
        index = 0  
        new_string = listname[index]  
        while index < len(listname)-1:
            new_string = new_string + listname[index + 1]

            index = index + 1
            if index == len(listname)-1:
                print('\n') 
                print(new_string)

    elif listname[len(listname) - 1] == '8':
         listname[len(listname) - 1] = 'and ' + listname[len(listname) -1]
         index = 0  
         new_string = listname[index]  
         while index < len(listname)-1:
            new_string = new_string + listname[index + 1]

            index = index + 1
            if index == len(listname)-1:
                print('\n') 
                print(new_string)

    elif listname[len(listname) - 1] == '9':
         listname[len(listname) - 1] = 'and ' + listname[len(listname) -1]
         index = 0  
         new_string = listname[index]  
         while index < len(listname)-1:
            new_string = new_string + listname[index + 1]

            index = index + 1
            if index == len(listname)-1:
                print('\n') 
                print(new_string)

    elif listname[len(listname) - 1] == 'a':
        listname[len(listname) - 1] = 'and ' + listname[len(listname) -1] #This is where I need the help in this elif statement....
        index = 0  
        new_string = listname[index]  
        while index < len(listname)-1:
            new_string = new_string + listname[index + 1]

            index = index + 1
            if index == len(listname)-1:
                print('\n') 
                print(new_string)

    else:
        print('\n') 
        print('Please enter lower case letters')
        exit

commacode(my_input)

Answer 1

为什么这么久？这是我的：

spam = ['apple', 'bananas', 'tofu', 'cats']

def func(a):
    a[-1] = 'and '+ a[-1]
    print(a)

func(spam)

顺便说一句，我正在读这本书，但我还没有达到其他的东西，我是否回答了你的问题？

Answer 2

感谢您的努力。它并没有完全回答我的问题。来自另一个论坛的代码确实回答了我的问题：

#Celine Hagbard from reddit.com slightly modified. It works!
s = input('Please enter a list of words and or numbers separated by commas:\n')
print(" and ".join(s.rsplit(",",1)))

是的，比我能管理的线少得多。

Answer 3

spam = ['apples', 'bananas', 'tofu', 'cats']

# function
def func(list):        
    string = ''        
    for item in list:
        string = string + str(item)

        # adding 'and' as last second item in the string
        if list.index(item) == (len(list)-2):
            string = string + ', and '

        # No comma after last item in the string
        elif list.index(item) == (len(list)-1):
            string = string

        else:
            string = string + ', '

    return string

print(func(spam))

输出

苹果，香蕉，豆腐和猫

Answer 4

spam = [1, 2, 3, 4, 'jeremy', 'anna']

# Function

def func(list):        
    string = ''        
    for item in list:
        string = string + str(item)

        # adding 'and' as last second item in the string
        if list.index(item) == (len(list)-2):
            string = string + ', and '

        # No comma after last item in the string
        elif list.index(item) == (len(list)-1):
            string = string

        else:
            string = string + ', '

    return string

# function calling

print(func(spam))

输出

1、2、3、4，杰里米和安娜

第4章逗号代码 - 扩展名

4 个答案:

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