In [1]: from itertools import chain, repeat, islice
   ...:
   ...: def pad_infinite(iterable, padding=None):
   ...:    return chain(iterable, repeat(padding))
   ...:
   ...: def pad(iterable, size, padding=None):
   ...:    return islice(pad_infinite(iterable, padding), size)
   ...:
In [2]: from collections import defaultdict
In [3]: import pandas as pd
In [4]: mb_funcs = defaultdict(list)
In [5]: with open("new-mb-funcs.txt", "r") as new_mb_funcs:
   ...:     for line in new_mb_funcs:
   ...:         mb_funcs[line.split()[-1].rstrip('(')].append(line.split()[1])
In [7]: for key in mb_funcs.keys():
   ...:     mb_funcs[key] = list(pad(mb_funcs[key], 150, padding=''))
In [8]: df = pd.DataFrame(mb_funcs)
In [9]: df.to_csv("mb_func_locations.csv", index=None, header=True)