CODEWITHSUNDEEP
pythonregexpandas
Mofaq
Mofaq

Reputation: 23

how to loop adding new column to pandas dataframe with value is based on other column value

Please I have dataframe with four columns that are [keys, summary, description, and summary_description], so iam dealing with summary_description, trying to apply RegEx and extract the new result in a [New_column], so I have done the looping but Iam not sure what is the problem not working getting error. Please if anyone could help, I would really appreciate it. 

import pandas as pd
import re
dataf= pd.read_excel(r'C:\Users\malotaibi\Desktop\Last update\result.xlsx')
dataf
dataf.head(5)
dataf['New_Column'][i] = re.sub('[^A-Za-z0-9]+', ' ', dataf['Summary_Description'][i])
print (dataf['New_column'][i])

Error:

KeyError: 'New_Column'

Upvotes: 1

Views: 59

Answers (2)

SteelFeather
SteelFeather

Reputation: 1680

You can do it like this:

dataf['New_Column'] = dataf['Summary_Description'].str.replace('[^A-Za-z0-9]+', ' ')

Upvotes: 1

Jamie J
Jamie J

Reputation: 1305

You have tried to add to the 'New Column' key before creating it. So do 

import pandas as pd
import re
dataf= pd.read_excel(r'C:\Users\malotaibi\Desktop\Last update\result.xlsx')
dataf
dataf.head(5)
dataf['New_Column'] = 1 # this will create the new_column entry and set all its values to 1

You can now loop through this and set each value to what you want. I assume you're going for something like:

for i in range(len(dataf['Summary_Description'])):
    dataf['New_Column'][i] = re.sub('[^A-Za-z0-9]+', ' ', dataf['Summary_Description'][i])

Upvotes: 0

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