Convert a column containing a list of dictionaries to multiple columns in pandas dataframe

Question

I have a Pandas dataframe like :

pd.DataFrame({\'a\':[1,2], \'b\':[[{\'c\':1,\'d\':5},{\'c\':3, \'d\':7}],[{\'c\':10,\'d\':50}]]})
Out[2]: 
   a                     


        

Answer 1

You can use concat with list comprehension:

df = pd.concat([pd.DataFrame(x) for x in df['b']], keys=df['a'])
       .reset_index(level=1, drop=True).reset_index()

print (df)
   a   c   d
0  1   1   5
1  1   3   7
2  2  10  50

EDIT:

If index is unique, then is possible use join for all columns:

df1 = pd.concat([pd.DataFrame(x) for x in df['b']], keys=df.index)
        .reset_index(level=1,drop=True)
df = df.drop('b', axis=1).join(df1).reset_index(drop=True)
print (df)
   a   c   d
0  1   1   5
1  1   3   7
2  2  10  50

I try simplify solution:

l = df['b'].str.len()
df1 = pd.DataFrame(np.concatenate(df['b']).tolist(), index=np.repeat(df.index, l))
df = df.drop('b', axis=1).join(df1).reset_index(drop=True)
print (df)
   a   c   d
0  1   1   5
1  1   3   7
2  2  10  50