import pandas as pd
df = pd.DataFrame([{'var1': 'a,b,c', 'var2': 1, 'var3': 'XX'},
{'var1': 'd,e,f,x,y', 'var2': 2, 'var3': 'ZZ'}])
print(df)
reshaped = \
(df.set_index(df.columns.drop('var1',1).tolist())
.var1.str.split(',', expand=True)
.stack()
.reset_index()
.rename(columns={0:'var1'})
.loc[:, df.columns]
)
print(reshaped)
Output:
var1 var2 var3
0 a,b,c 1 XX
1 d,e,f,x,y 2 ZZ
var1 var2 var3
0 a 1 XX
1 b 1 XX
2 c 1 XX
3 d 2 ZZ
4 e 2 ZZ
5 f 2 ZZ
6 x 2 ZZ
7 y 2 ZZ