CODEWITHSUNDEEP
pandasdataframe
Nabih Bawazir
Nabih Bawazir

Reputation: 7255

How do I flattening a MultiIndex column

Here's my data

              customer_id   value
var_name                    Value_1     Value_2 
0             1             70          80

I want to make it

var_name      customer_id   Value_1     Value_2 
0             1             70          80

what I did is df.columns = ['customer_id', 'Value_1', 'Value_2'] but this is to prone to mistake since I had hundreds of columns

How suppose I do this?

Upvotes: 1

Views: 48

Answers (1)

jezrael
jezrael

Reputation: 862591

You always get MultiIndex, because no parameter values with one value:

df = data.pivot_table(index='customer_id', 
                      columns='var_name', 
                      fill_value=0, 
                      aggfunc='max')

#columns names of first level  are not removed 
df.columns = df.columns.map('_'.join)
#first level removed, but possible duplicated columns names, so not recommended
#df.columns = df.columns.droplevel(0)

df = df.reset_index()

If scalar in value (processes one column only):

df = data.pivot_table(index='customer_id', 
                      columns='var_name', 
                     fill_value=0, 
                     values='age',
                     aggfunc='max')

Upvotes: 1

Related Questions