Python: elegant solution to transform the following string to a dictionary

Question

I encountered a string input in the following format:

'1:[2,3],4:[1],3:[4],2:[4]'

How to transform it into the following format:

{1:[2,3],4:[1],3:[4],2:[4]}

Thanks!

Answer 1

• Copied from python doc "Safely evaluate an expression node or a string containing a Python literal or container display"
• you can read more info here. https://docs.python.org/3/library/ast.html#ast.literal_eval

from ast import literal_eval

d = literal_eval('{1:[2,3],4:[1],3:[4],2:[4]}')

print(d)

Output:

{1: [2, 3], 4: [1], 3: [4], 2: [4]}

Answer 2

Some fun with regex :)

import re

parse_re = r"(\d+):\[([^\]]*)\]"

raw_str = '1:[2,3],4:[1],3:[4],2:[4]'

res_dict = {}

for curr_match in re.finditer(parse_re, raw_str):
    dict_key, dict_val_str = curr_match.groups()
    dict_key = int(dict_key)
    dict_val = [int(item) for item in dict_val_str.split(',')]
    res_dict[dict_key] = dict_val

---

I'd like to dedicate this hardcore fun method to Derek Eden.

import re

parse_re = r"(\d+):\[([^\]]*)\]"

raw_str = '1:[2,3],4:[1],3:[4],2:[4]'

match_groups = (curr_match.groups() for curr_match in re.finditer(parse_re, raw_str))

res_dict = {int(curr_key): [int(item) for item in curr_val.split(',')] for curr_key, curr_val in match_groups}