如何使用列表中的每個項目僅循環一次列表以在​​Python中的另一個列表的開頭插入？

Question

我是Python的新手，在完成任務的任務時遇到了麻煩。 我已經定義了一個除了以下區域之外運行良好的函數：我正在處理10個字符串的列表，我需要將此列表中的每個字符串僅插入到相應的10個字符串的隨機列表的開頭。使用sys.argv從終端中取出文件（意味着有10個文件，我的列表中有一個字符串對應每個文件）。 我知道我必須使用.insert(0, new_string)方法從我的10個字符串列表中插入新字符串。

這是我的功能的摘錄，顯示了我迄今為止嘗試實現的目的：

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)

當我運行這段代碼時，我得到一個列表的輸出，其中new_list中的每個元素都插入到我的randomlist元素之前。 這導致20個元素的列表，它應該只有11個。

輸出應該是這樣的（在使用sys.argv將函數應用於10個文件之后），其中rstring對應於我的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"]

我也嘗試了其他的東西，但這是我可以得到輸出的最簡單的方法。作為回顧，我需要使用new_list每個元素一次（按從左到右的順序）並將其插入我的randomlist的開頭。 我正在使用的每個文件都有一個randomlist ，我通過sys.argv調用它們我相信它會涉及某種類型的for循環和可能的元組，但我不知道如何讓它們做我做的事情需要他們這樣做。 此外，我不允許硬編碼任何東西。

Answer 1

在您的代碼中，您將新元素插入到相同且唯一的列表randomlist列表中，這就是為什么它們最終堆積在一起的原因。

您可以在randomlist的開頭（副本）添加元素item （不影響randomlist本身），如下所示：

[item] + randomlist

要一次創建所有輸出，只需將其嵌套在列表推導中：

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們，您可以這樣做：

for item in new_list:
    print [item] + randomlist

Answer 2

嘗試這個，

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