How to tabulate correctly repeated blocks?

[Xiesxes]

Hello to all,

Maybe someone could help me with this:

I have this file, for which I want to tabulate its values. Keys from a to c begin a new sequence of values (a block) and these 3 keys are always present. After keys a, b and could come values d to g.

SOME TEXT SOME TEXT
SOME TEXT SOME TEXT
SOME TEXT SOME TEXT SOME TEXT
SOME TEXT

                         a = 1
                         b = 5
                         c = 3

                         d = 0
                         e = 0

                         d = 4
                         e = 1
                         g = 1


blah blah

blah blah

///   FINISH


                         a = 3
                         b = 2
                         c = 8
                         d = 6
                         e = 9
                         f = 3



blah blah

blah blah

///   FINISH


                         a = 7
                         b = 2
                         c = 2
                         d = 9
                         e = 0

                         d = 1
                         e = 4

                         d = 7
                         e = 0
                         f = 1

                         d = 1
                         g = 8


blah blah

blah blah

///   FINISH

My goal is to tabulate it like image below using the list structure Pandas needs:


I'm currently able to store the file content in a list (lst) and then I try to group-by that list, getting this output(m2):

import re, pprint
from collections import defaultdict

file = 'file.txt'
f=open(file,"r").read().splitlines()

lst=[]
for line in f:
    if re.match(r'[ \t]', line):
        lst.append(line.replace(' ', '').split('='))

print(lst)


m2 = defaultdict(list)
for k, v in lst:
    m2[k].append(v)

>>> pprint.pprint(m2)
defaultdict(<class 'list'>,
            {'a': [1, 3, 7],
             'b': [5, 2, 2],
             'c': [3, 8, 2],
             'd': [0, 4, 6, 9, 1, 7, 1],
             'e': [0, 1, 9, 0, 4, 0],
             'f': [3, 1],
             'g': [1, 8]})

My issue is that the correct input(m2) to feed Pandas dataframe would be like this:

m2 = {
  'a': [1,1,3,7,7,7,7], 
  'b': [5,5,2,2,2,2,2],
  'c': [3,3,8,2,2,2,2],
  'd': [0,4,6,9,1,7,1],
  'e': [0,1,9,0,4,0,''],
  'f': ['','',3,'','',1,''],
  'g': [1,'','','','','',8],
 }

That needs a kind of fill down(only for keys a, b, c) and fill with blanks(for keys d to g) when needed.


Already asked on SO but no answers.