如何使用列表中的每个项目仅循环一次列表以在​​Python中的另一个列表的开头插入？

Question

我是Python的新手，在完成任务的任务时遇到了麻烦。 我已经定义了一个除了以下区域之外运行良好的函数：我正在处理10个字符串的列表，我需要将此列表中的每个字符串仅插入到相应的10个字符串的随机列表的开头。使用sys.argv从终端中取出文件（意味着有10个文件，我的列表中有一个字符串对应每个文件）。 我知道我必须使用.insert(0, new_string)方法从我的10个字符串列表中插入新字符串。

这是我的功能的摘录，显示了我迄今为止尝试实现的目的：

randomlist = (list(map(choice, old_list)))
new_list = ["string1", "string2", "string3", "string4", "string5", "string6", "string 7", "string8", "string9", "string10"]
for new_string in new_list:
    randomlist.insert(0, new_string)

当我运行这段代码时，我得到一个列表的输出，其中new_list中的每个元素都插入到我的randomlist元素之前。 这导致20个元素的列表，它应该只有11个。

输出应该是这样的（在使用sys.argv将函数应用于10个文件之后），其中rstring对应于我的randomlist的字符串：

["string1", "rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
["string2", "rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
["string3", "rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
["string4", "rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
["string5", "rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
["string6", "rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
["string7", "rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
["string8", "rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
["string9", "rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
["string10", "rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]

我也尝试了其他的东西，但这是我可以得到输出的最简单的方法。作为回顾，我需要使用new_list每个元素一次（按从左到右的顺序）并将其插入我的randomlist的开头。 我正在使用的每个文件都有一个randomlist ，我通过sys.argv调用它们我相信它会涉及某种类型的for循环和可能的元组，但我不知道如何让它们做我做的事情需要他们这样做。 此外，我不允许硬编码任何东西。

Answer 1

在您的代码中，您将新元素插入到相同且唯一的列表randomlist列表中，这就是为什么它们最终堆积在一起的原因。

您可以在randomlist的开头（副本）添加元素item （不影响randomlist本身），如下所示：

[item] + randomlist

要一次创建所有输出，只需将其嵌套在列表推导中：

all_outputs = [[item] + randomlist for item in new_list]
for output in all_outputs:
    print output

或者如果您只需要打印它们，您可以这样做：

for item in new_list:
    print [item] + randomlist

Answer 2

尝试这个，

import random

list1 = ["rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
list2 = ["rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
list3 = ["rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
list4 = ["rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
list5 = ["rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
list6 = ["rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
list7 = ["rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
list8 = ["rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
list9 = ["rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]
list10 = ["rstring1", "rstring2", "rstring3", "rstring4", "rstring5", "rstring6", "rstring7", "rstring8", "rstring9", "rstring10"]

lists = [list1, list2, list3, list4, list5, list6, list7, list8, list9, list10]

new_list = ["string1", "string2", "string3", "string4", "string5", "string6", "string7", "string8", "string9", "string10"]
for new_string in new_list:
    randomlist = random.choice(lists) #Selects a random list from pool
    randomlist.insert(0, new_string)
    lists.remove(randomlist) #Removes list from pool once it has been selected

print list1
print list2
print list3
print list4
print list5
print list6
print list7
print list8
print list9
print list10