如何检查一个元素是否存在于python的多个列表中

Question

companies = ['apple','google','tesla','facebook','cisco']
list_1 = ['apple','google','tesla','facebook']
list_2 = ['google','tesla','facebook']
list_3 = ['apple','tesla','cisco']
list_4 = ['apple','google','tesla']
list_5 = ['google','tesla','facebook']

我有熊猫 df 如下 - COMPANY_DF

+--------+---------------------------------------+---------------+
|column1 |             column2                   |   column3     |
+------------------------------------------------+---------------|
|apple   | [list_2,list_3,list_4]                |               |
|google  | [list_1,list_2,list_3,list_5]         |               |
|tesla   | [list_1,list_2,list_3,list_4,list_5]  |               |
|facebook| [list_1,list_2,list_5]                |               |
|cisco   | [list_3]                              |               |
+------------------------------------------------+---------------+

问题 - 对于column3我必须从column2的列表中找到其他元素例如 - 对于column1 row 1 apple 我必须在[list_2,list_3,list_4] ( column2 row 1) 中找到其他公司的苹果

我的方法——

for i in range(0, len(COMPANY_DF['column2'])):
    column3_list = []    
    for company in companies:
        for j in range(0, len(COMPANY_DF['column2'].loc[i])):
            if company in COMPANY_DF['column2'].loc[i][j]:
                company.append(column3_list)
            else:
                print('Not there')
    COMPANY_DF['column3'].loc[i] = column3_list 

我对这个 if 语句有疑问 -

if company in COMPANY_DF['column2'].loc[i][j]:
if company in COMPANY_DF['column2'].loc[i][j] is 
giving 'list_2' instead of list_2 I believe that's why it's failing. 

任何帮助表示赞赏。

Answer 1

这是我的方法：

companies = ['apple','google','tesla','facebook','cisco']
list_1 = ['apple','google','tesla','facebook']
list_2 = ['google','tesla','facebook']
list_3 = ['apple','tesla','cisco']
list_4 = ['apple','google','tesla']
list_5 = ['google','tesla','facebook']

list_of_lists = [f'list_{i}' for i in range(1, 6)]
# will create a string named the same for each of the lists,
# so it can be added to the list of mentions later, and also evaluated.

company_mentions = []
for company in companies:
    mentions = [mention for mention in list_of_lists if company in eval(mention)]
    # a list of the lists that a particular company has been mentioned in.

    company_mentions.append(mentions)
    # will append a list of the lists that company is mentioned in.

希望这可以帮助。

编辑：如果您希望拥有整个列表，则可以在附加时在mentions周围添加eval 。 什么对你最有效。