Convert column to row in Python Pandas

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Question :

Convert column to row in Python Pandas

I have the following Python pandas dataframe:

     fruits | numFruits
---------------------
0  | apples |   10
1  | grapes |   20
2  |  figs  |   15

I want:

                 apples | grapes | figs
-----------------------------------------
Market 1 Order |    10  |   20   |  15

I have looked at pivot(), pivot_table(), Transpose and unstack() and none of them seem to give me this. Pandas newbie, so all help appreciated.

Asked By: Reise45

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Answer #1:

You need set_index with transpose by T:

print (df.set_index('fruits').T)
fruits     apples  grapes  figs
numFruits      10      20    15

If need rename columns, it is a bit complicated:

print (df.rename(columns={'numFruits':'Market 1 Order'})
         .set_index('fruits')
         .rename_axis(None).T)
                apples  grapes  figs
Market 1 Order      10      20    15

Another faster solution is use numpy.ndarray.reshape:

print (pd.DataFrame(df.numFruits.values.reshape(1,-1), 
                    index=['Market 1 Order'], 
                    columns=df.fruits.values))

                apples  grapes  figs
Market 1 Order      10      20    15

Timings:

#[30000 rows x 2 columns] 
df = pd.concat([df]*10000).reset_index(drop=True)    
print (df)


In [55]: %timeit (pd.DataFrame([df.numFruits.values], ['Market 1 Order'], df.fruits.values))
1 loop, best of 3: 2.4 s per loop

In [56]: %timeit (pd.DataFrame(df.numFruits.values.reshape(1,-1), index=['Market 1 Order'], columns=df.fruits.values))
The slowest run took 5.64 times longer than the fastest. This could mean that an intermediate result is being cached.
1000 loops, best of 3: 424 ┬Ás per loop

In [57]: %timeit (df.rename(columns={'numFruits':'Market 1 Order'}).set_index('fruits').rename_axis(None).T)
100 loops, best of 3: 1.94 ms per loop
Answered By: jezrael

Answer #2:

pd.DataFrame([df.numFruits.values], ['Market 1 Order'], df.fruits.values)

                apples  grapes  figs
Market 1 Order      10      20    15

Refer to jezrael’s enhancement of this concept. df.numFruits.values.reshape(1, -1) is more efficient.

Answered By: piRSquared

Answer #3:

You can use transpose api of pandas as follow:

df.transpose()

Considering df as your pandas dataframe

Answered By: Akash Desarda

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