当值存在时，将列索引作为值

Question

I need do create some additional columns to my table or separate table based on following:

I have a table

and I need to create additional columns where the column indexes (names of columns) will be inserted as values. Like this:

How to do it in pandas? Any ideas? Thank you

Answer 1

If need matched columns only for 1 values:

df = (df.set_index('name')
        .eq(1)
        .dot(df.columns[1:].astype(str) + ',')
        .str.rstrip(',')
        .str.split(',', expand=True)
        .add_prefix('c')
        .reset_index())
print (df)

Explanation :

Idea is create boolean mask with True for values which are replaced by columns names - so compare by DataFrame.eq by 1 and used matrix multiplication by DataFrame.dot by all columns without first with added separator. Then remove last traling separator by Series.str.rstrip and use Series.str.split for new column, changed columns names by DataFrame.add_prefix .

Another solution:

df1 = df.set_index('name').eq(1).apply(lambda x: x.index[x].tolist(), 1)
df = pd.DataFrame(df1.values.tolist(), index=df1.index).add_prefix('c').reset_index()