How to move text from old column to newly created columns pandas-CodePudding

I have the following code which is applied just for one column named 'Desc'. How can i change the code to apply it for two columns? 'Desc' and 'Desc1'?

df = pd.DataFrame({'Desc':['cat is black','dog is white']})
kw = ['cat','dog']
for k in kw:
   df[k   ' col'] = df.Desc.map(lambda s: s if k in s else '' )

[The output with just one column 'Desc' is:]

But now i want to use this function to do the selection of two colums Desc and Desc1

CodePudding user response：

You didn't show what result you expect but you can always use

df[k   ' col'] = df.Desc.map(...)   ","   df.Desc1.map(...)

But this will add , in empty cell and it will repeate duplicated values.

import pandas as pd

df = pd.DataFrame({
    'Desc':  ['cat is black', 'dog is white'],
    'Desc1': ['cat is white', 'dog is white'],
})

kw = ['cat','dog']
for k in kw:
   df[k   ' col'] = df.Desc.map(lambda s: s if k in s else '')   ','   df.Desc1.map(lambda s: s if k in s else '')
   
print(df.to_string())

Result:

           Desc         Desc1                    cat col                    dog col
0  cat is black  cat is white  cat is black,cat is white                          ,
1  dog is white  dog is white                          ,  dog is white,dog is white

But you can also use .apply(function, args=[...], axis=1) to send full row to function and run more complex code in function

import pandas as pd

df = pd.DataFrame({
    'Desc':  ['cat is black', 'dog is white'],
    'Desc1': ['cat is white', 'dog is white'],
})

def select(row, word):
    result = []

    if word in row['Desc']:
        result.append(row['Desc'])

    if word in row['Desc1']:
        result.append(row['Desc1'])
        
    # skip duplicated
    if len(result) > 1 and result[0] == result[1]:
        result = result[:1]
        
    return ",".join(result)
    
kw = ['cat','dog']
for word in kw:
   df[f'{word} col'] = df.apply(select, args=[word], axis=1)
   
print(df.to_string())

Result:

           Desc         Desc1                    cat col       dog col
0  cat is black  cat is white  cat is black,cat is white              
1  dog is white  dog is white                             dog is white

CodePudding user response：

import pandas as pd


df = pd.DataFrame({'Desc':['cat is black','dog is white']})
kw = ['cat','dog']

i = 0 #iterator
for k in kw:
    #Creates an empty column
    df[k   'col'] = "" 
    #Assigns the value in the cell based on its location in df["Desc"]
    df[k   'col'][i] = df["Desc"][i]
    i = i 1 #iterates