Conditional row and column-wise replace of strings

Question

Given the following df:

df_test = pd.DataFrame({'0' : ['find expert model','NR','R','NR'],
               '1' : ["news recommend", "NR" ,"NR", "NR"],
               '2' : ["a recommend", "R" , "NR", "NR"],
               '3' : ["a web recommend", "R", "NR", "R"]})
df_test

    0                   1               2           3
0   find expert model   news recommend  a recommend a web recommend
1   NR                  NR              R           R
2   R                   NR              NR          NR
3   NR                  NR              NR          R

I am trying to obtain this form of the df:

    0                   1               2           3
0   NR                  NR              a recommend a web recommend
1   find expert model   NR              NR          NR
2   NR                  NR              NR          a web recommend

The goal here is to replace every string R in a certain cell with the string from the first row of the distinct column. The replacing process should begin at the row with index 1.

Any ideas? Thanks in advance!

can you be more explicit in what you're trying to achieve?

nidabdella
– nidabdella

2019-07-25 19:16:24 +00:00
Commented Jul 25, 2019 at 19:16 — nidabdella
– nidabdella, Commented Jul 25, 2019 at 19:16

Scott Boston · Accepted Answer · 2019-07-25 19:28:29Z

3

Try this using apply, replace, and drop:

df_test.apply(lambda x: x.replace('R', x.iloc[0])).drop(0).reset_index(drop=True)

Output:

                   0   1            2                3
0                 NR  NR  a recommend  a web recommend
1  find expert model  NR           NR               NR
2                 NR  NR           NR  a web recommend

answered Jul 25, 2019 at 19:28

Scott Boston

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Comments

Vink · Accepted Answer · 2019-07-25 19:36:56Z

2

Try this:

for col in df.columns:
    df.loc[df[col] == 'R', col] = df.loc[0, col]
df = df.drop(0)
df.reset_index(drop=True, inplace=True)

Results in:

                   0               1            2                3
0                 NR              NR  a recommend  a web recommend
1  find expert model              NR           NR               NR
2                 NR              NR           NR  a web recommend

edited Jul 25, 2019 at 19:36

answered Jul 25, 2019 at 19:31

Vink

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