how to convert series of lists into dataframe in python?

Question

I have below format of dataframe

student   marks
a         [12,12,34]
b         [34,35]
c         [23,45,23]

i want it to convert to like below

student marks_1  marks_2 marks_3
a       12        12      34
b       34        35      Nan
c       23        45      23

how to achieve this ? any help please

Answer 1

Use join new DataFrame created by extracted column marks by pop, convert to lists and use rename for columns by custom lambda function:

f = lambda x: 'marks_{}'.format(x + 1)
df = df.join(pd.DataFrame(df.pop('marks').values.tolist()).rename(columns=f))
print (df)
  student  marks_1  marks_2  marks_3
0       a       12       12     34.0
1       b       34       35      NaN
2       c       23       45     23.0

Detail:

print (pd.DataFrame(df.pop('marks').values.tolist()))
    0   1     2
0  12  12  34.0
1  34  35   NaN
2  23  45  23.0

Answer 2

Try

dfr = pd.concat([df.student, df.marks.apply(lambda el: pd.Series(
    el, index=['marks_{}'.format(i + 1) for i in range(len(el))]))], axis=1)

The code above create an index from each element in marks then concatenate the result with the student column,

The output:

dfr

  student  marks 1  marks 2  marks 3
0       a     12.0     12.0     34.0
1       b     34.0     35.0      NaN
2       c     23.0     45.0     23.0