Merge two equal-length lists into a dictionary, mapping one-to-many

two-equal-lists-merge.py

Lst1 = ['11', '13', '11', '12', '11', '13', '12', '12', '12', '13', '11']
Lst2 = ['1/41', '1/34', '1/37', '1/47', '1/41', '1/33', '1/46', '1/45', 'p4', 'p5', 'p6']

Dict1 = {'11': ['1/41', '1/37', '1/141', 'p6'],
         '12': ['1/47', '1/33', '1/46', 'p4'],
         '13': ['1/34', '1/33', 'p5']}
         
         
Dict1 = {}
for key, val in zip(Lst1, Lst2):
    Dict1.setdefault(key, []).append(val)

Dict1
{'11': ['1/41', '1/37', '1/41', 'p6'], '13': ['1/34', '1/33', 'p5'], '12': ['1/47', '1/46', '1/45', 'p4']}
from pprint import pprint

pprint(Dict1)
{'11': ['1/41', '1/37', '1/41', 'p6'],
 '12': ['1/47', '1/46', '1/45', 'p4'],
 '13': ['1/34', '1/33', 'p5']}