CODEWITHSUNDEEP
pythonpandas
PV8
PV8

Reputation: 6280

Duplicate row for every different entry in one specific column

I want to create a duplicate for every row, but only if the row has a new entry in a specific column and on top want to keep some columns empty then. So the dataframe looks like:

number value  area typ
1       10    B     A
2       20    B     A
3       10    B     B
4       20    B     B
5       30    B     B

the outcome of my expected dataframe would be:

number value  area typ
              B     A
1       10    B     A
2       20    B     A
              B     B
3       10    B     B
4       20    B     B
5       30    B     B

so that it gets duplicated based on a new entry of typ (a typ which was not in the rows before) and the columns number and value are kept empty.

Upvotes: 0

Views: 69

Answers (1)

Quang Hoang
Quang Hoang

Reputation: 150825

You can drop duplicate and concat:

pd.concat((df.drop_duplicates(['area','typ']).assign(number='',value=''), df)
         ).sort_index(kind='mergesort')

Output:

  number value area typ
0                 B   A
0      1    10    B   A
1      2    20    B   A
2                 B   B
2      3    10    B   B
3      4    20    B   B
4      5    30    B   B

Update: For several columns that needs to be emptied:

cols = ['area','typ']
new_df = df.drop_duplicates(cols)

for col in new_df.columns:
    if col not in cols: new_df[col] = ''

pd.concat((new_df, df)).sort_index(kind='mergesort')

Upvotes: 3

Related Questions