find mutlible list values inside a dataframe

Question

I have a list name as list_1 like this:

[["xx ",'yy']
[["gg ",'xx']
[["xx ",'gg']]

Also, I have a df like this:

  column1  column2............ coulymn_N
0  xx        gg                 gg
1  gg        xx                 yy
2  xx        something else     nan

I want to search line by line the list_1 into the df and return the matching

So for example an output for the first line of list_1 inside df could be

  column1  
0  xx

and also

  column_N
1   yy

The problem that I have is that in my list i have more than one value ("xx ", and "yy") and so I am confusing. I do not think so that I can use the isin method.

Any ideas?

Hello, I do not understand your question. Take a look at https://stackoverflow.com/questions/20109391/how-to-make-good-reproducible-pandas-examples — Steele Farnsworth, Nov 18 '21 at 16:20

score 1 · Accepted Answer · answered Nov 19 '21 at 08:58

Suppose you have a list like:

list_of_lists = [["xx", "yy"], ["gg", "xx"], ["xx", "gg"]]

and a pandas dataframe like this:

import pandas as pd

df = pd.DataFrame(
    {
        "column1": ["xx", "yy", "aa"],
        "column2": ["yy", "gg", "aa"],
        "column3": ["gg", "aa", "hh"],
    }
)

You can then go through each sub_list of the list_of_lists and check if each item of the sub_list exists in any of the columns of the dataframe. In this case you can print the result:


for sub_list in list_of_lists:
    print("\n")
    print("Sub_list: ", sub_list)
    for item in sub_list:
        for col in df.columns:
            if item in df[col].values:
                print(df[col][df[col] == item].to_frame())

The above would print the following:

Sub_list:  ['xx', 'yy']
  column1
0      xx
  column1
1      yy
  column2
0      yy


Sub_list:  ['gg', 'xx']
  column2
1      gg
  column3
0      gg
  column1
0      xx


Sub_list:  ['xx', 'gg']
  column1
0      xx
  column2
1      gg
  column3
0      gg

can you explain me the last line print(dfcc[col][dfcc[col] == item].to_frame()) and especially this df[col][df[col]? — redplanet, Nov 20 '21 at 16:58
`[df[col] == item]` selects those instances where the value of the column `col` is equal to the `item`, which is for example `xx`. The `df[col]` before that just selects only the column `col`. So for example, if we are at the item `xx` and the `col` `column1`, it will find those rows where `column1` is equal to `xx` (item). Out of all these rows, we only want `column1` value through `df[col]`. — KostisPar, Nov 21 '21 at 13:38

find mutlible list values inside a dataframe

1 Answers1