Reshaping a pandas dataframe by repeating rows

Question

I am new to Python especially Pandas. I have one dataframe like

-----------------------------------------------------
Id     Name    Salary    desc1     des         


        

Answer 1

You need set_index + stack:

df = df.set_index(['Id','Name','Salary'])
       .stack()
       .reset_index(level=3, drop=True)
       .reset_index(name='Variable')

print (df)
   Id  Name  Salary Variable
0   1  ABC1    2000       x1
1   1  ABC1    2000       y1
2   1  ABC1    2000       z1
3   2  ABC2    5000       x2
4   2  ABC2    5000       y1
5   2  ABC2    5000       z2

If sorting first 3 columns is not necessary:

Use melt:

df = df.melt(['Id','Name','Salary'], value_name='Variable').drop('variable', axis=1)
print (df)
   Id  Name  Salary Variable
0   1  ABC1    2000       x1
1   2  ABC2    5000       x2
2   1  ABC1    2000       y1
3   2  ABC2    5000       y1
4   1  ABC1    2000       z1
5   2  ABC2    5000       z2

lreshape is now undocumented, but is possible in future will by removed (github link).

df = pd.lreshape(df, {'Variable':['desc1','desc2','desc3']})
print (df)
   Id  Name  Salary Variable
0   1  ABC1    2000       x1
1   2  ABC2    5000       x2
2   1  ABC1    2000       y1
3   2  ABC2    5000       y1
4   1  ABC1    2000       z1
5   2  ABC2    5000       z2