CODEWITHSUNDEEP
pythonpython-3.xpandas
RustyShackleford
RustyShackleford

Reputation: 3677

How to flip values in columns into column headers?

I have a df that looks like this:

    Id   field          value
0   1    first_name      a
1   1    number          123
2   1    last_name       aa
0   2    first_name      b
1   2    number          456
2   2    last_name       bb
3   2    type            p

Each Id has a different length of index and roughly the same field types but some have more some have less.

How do I flip the df so that fields are columns and values are underneath them?

Like so: 

    Id   first_name   number   last_name    type
0   1      a          123         aa    
1   2      b          456         bb         p

Upvotes: 1

Views: 117

Answers (2)

ALollz
ALollz

Reputation: 59579

This is also just .pivot

df.pivot(index='Id', columns='field', values='value').reset_index()
#field  Id first_name last_name number type
#0       1          a        aa    123  NaN
#1       2          b        bb    456    p

If you get ValueError, this likely means that you have a row duplicated on ['Id', 'field']. This will make it work, but will chose the value as whichever row appears first in your DataFrame.

pd.pivot_table(df, index='Id', columns='field', values='value', aggfunc='first')

Upvotes: 2

user3483203
user3483203

Reputation: 51165

I think you want to set_index and unstack:

out = df.set_index(['Id', 'field']).unstack()
out.columns = out.columns.get_level_values(1)
out.reset_index()


field  Id first_name last_name number type
0       1          a        aa    123  NaN
1       2          b        bb    456    p

Upvotes: 3

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