How to widen a dataframe - pandas

Question

Basically i want to just flatten ( maybe not good term )

for example having dataframe:

    A      B            C
0   1  [1,2]      [1, 10]
1   2  [2,         


        

Answer 1

General solution working also if lists have differents lengths:

df1 = pd.DataFrame(df['B'].values.tolist())
df2 = pd.DataFrame(df['C'].values.tolist())

df = pd.concat([df[['A']], df1, df2], axis=1)
df.columns = [df.columns[0]] + [f'B{i+1}' for i in range(len(df.columns)-1)]
print (df)
   A  B1  B2  B3  B4
0  1   1   2   1  10
1  2   2  14   2  18

If same size:

df1 = pd.DataFrame(np.array(df[['B','C']].values.tolist()).reshape(len(df),-1))
df1.columns = [f'B{i+1}' for i in range(len(df1.columns))]
df1.insert(0, 'A', df['A'])
print (df1)
   A  B1  B2  B3  B4
0  1   1   2   1  10
1  2   2  14   2  18