如何在 python 中将行值转换为列名和与列值相同的列名？

Question

I want to convert row values as column names and those column names would be the column values. I have tried with pivot but it is not giving desired output.

Data:
col1   col2   col3 col4
x1      y1      z1   a1
x1      y1      z1    a2
x1      y1      z1    a3

I have tried like below:

Data.pivot(columns='Col4', values='col4')

Output:
a1  a2   a3
a1 NAN   NAN
NAN a2   NAN
NAN  NAN  a3

Desired output:

col1 col2 col3  a1  a2 a3
x1     y1   z1  a1  a2 a3

Answer 1

You can use pivot , but you need to specify the index argument to keep your "col1", "col2", "col3". Once you do that, you can clean up the dataframe a little bit to get the result you want.

out = (df.pivot(index=["col1", "col2", "col3"], columns="col4", values="col4")
         .rename_axis(columns=None)
         .reset_index())

print(out)
  col1 col2 col3  a1  a2  a3
0   x1   y1   z1  a1  a2  a3

Steps

• pivot(...) : pivot the dataframe as desired. This makes a MultiIndex of "col1", "col2", and "col3". Then the actual columns & values from the value of "col4"
• rename_axis(columns=None) : pivot makes a columns an Index object with a name. I find that this name throws people off be adjusting how the dataframe is represented. Here I remove the name from the column Index so that it can be represented how OP expects
• reset_index() as stated earlier- pivot makes a MultiIndex of "col1", "col2", and "col3". We use reset_index() here to take these values and insert it into the actual data of the DataFrame instead of being a MultiIndex