I want to delete values from a column corresponding to values starting with a particular string in another column

Question

Remove the values in column titled “LogKOW” corresponding to the values starting with V-Mey_NA in the column titled “CAS”.

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https://archive.ics.uci.edu/ml/machine-learning-databases/00511/ — Prabal Bali, Apr 30 '20 at 18:36

score 0 · Answer 1 · answered May 02 '20 at 08:38

0

I guess this will work

for index in df.index:
    if(df['CAS'][index].find('V-Mey_NA') != -1):
        df['LogKOW'][index] = np.nan

answered May 02 '20 at 08:38

Maybe it would be better to use `.startswith('V-Mey_NA')` instead of `.find('V-Mey_NA') != -1`. – Gilles D. May 02 '20 at 12:17
I did this and it worked: `(c = 0 for i in df['CAS']: c +=1 if i[0:8] == 'V-Mey_NA': df['LogKOW'][c] = np.NaN df)` – Prabal Bali May 03 '20 at 10:34

score 0 · Answer 2 · edited May 02 '20 at 10:51

0

This might help in removing the values

x = df1["CAS"].str.startswith("V-Mey_NA")
n = np.arange(0,1058,1)
df1.drop(n[x])

edited May 02 '20 at 10:51

David Buck

answered May 02 '20 at 10:40

score 0 · Answer 3 · answered May 02 '20 at 10:56

0

Try this instead

import numpy as np
df['LogKOW'] = np.where(df.CAS.str.startswith('V-Mey_NA'),np.NaN,df['LogKOW'])

answered May 02 '20 at 10:56

Kartik Singhal

3 Answers3