[FIXED] Get the list of values/entries that are common to all the columns in a dataframe (or a csv file) in python

Issue

I have this setup of a pandas dataframe (or a csv file):

df = {
    'colA': ['aa', 'bb', 'cc', 'dd', 'ee'],
    'colB': ['aa', 'bb', 'dd', 'qq', 'ee'],
    'colC': ['aa', 'bb', 'cc', 'ee', 'dd'],
    'colD': ['aa', 'bb', 'ee', 'cc', 'dd']
}

The goal here is to get a list/column with the set of values that appear in all the columns or in other words the entries that are common to all the columns.

Required output:

col
aa
bb
dd
ee

or a output with the common value's list:

common_list = ['aa', 'bb', 'dd', 'ee']

I have a silly solution (but it doesn't seem to be correct as I am not getting what I want when implemented to my dataframe)

import pandas as pd

df = pd.read_csv('Bus Names Concat test.csv') #i/p csv file (pandas df converted into csv)

df = df.stack().value_counts() 
core_list = df[df>2].index.tolist() #defining the common list as core list
print(len(core_list))
df_core = pd.DataFrame(core_list)

print(df_core)

Any help/sugggestion/feedback to get the required o/p will be appreciated.

Solution

In your case

s = df.melt().groupby('value')['variable'].nunique()
outlist = s[s==4].index.tolist()
Out[307]: ['aa', 'bb', 'dd', 'ee']

Answered By - BENY