Pandas: Using apply to copy row values across specific columns into new column

Question

I'm trying to copy all of the values across a subset of rows into a new column using the apply function, but it seems to just copying the entire dataframe range. I'm receiving that subset of the dataframe as a result, though I'm expecting df.loc[index, 'consolidated_commentary'] to contain a concatenated version of the the text in the columns contained within all_commentary_columns

My code is:

 for index, row in df[all_commentary_columns].iterrows():
if pd.isna(row).prod():
    df.loc[index, 'new_col'] = 'good'
else:
    df.loc[index, 'new_col'] = 'bad'
    df.loc[index, 'consolidated_commentary'] = df[all_commentary_columns].apply(lambda x: x.loc[all_commentary_columns], axis=1)

what's `index` in `.loc[index]`? Please provide your sample data and expected output. — Quang Hoang, Sep 12 '19 at 22:05
See this answer: https://stackoverflow.com/questions/44497671/pandas-combine-columns-without-duplicates-find-unique-words-after-combining — Pilgrim, Sep 12 '19 at 22:15

score 0 · Answer 1 · answered Sep 12 '19 at 22:26

0

I pulled this from the answer I referenced in the comments:

df.loc[index, 'consolidated_commentary'] = df.loc[index, all_commentary_columns].astype(str).apply(lambda x: ' '.join(' '.join(x).split()),axis=1)

answered Sep 12 '19 at 22:26

Pilgrim

88
1
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Thanks for this, though it doesn't seem to concatenate the row values as expected :/ – Gregory Sep 13 '19 at 00:18

Pandas: Using apply to copy row values across specific columns into new column

1 Answers1