将字符串转换为 dict 并返回的优雅方法

Question

Is there an elegant one-liner to convert this type of string to dict? I googled now for an hour, but without several loops of splitting strings I can't get it to work.

Input  = "2:9, 6:90, 7:60"
Output = {'2': 9, '6': 90, '7': 60}

I would also need the reverse operation from dict to string.

Answer 1

Performance wise most efficient will be normal for loop:

my_string = "2:9, 6:90, 7:60"
my_dict = {}
for s in my_string.split(', '):
     k, v = s.split(":")
     my_dict[k] = int(v)

where my_dict will contain:

>>> my_dict
{'2': 9, '7': 60, '6': 90}

---

To get back the same string, you can perform .join() on dict.items() as:

>>> ", ".join("{}:{}".format(k, v) for k, v in my_dict.items())
'2:9, 7:60, 6:90'

Or, you can also type-cast the dict to string and do some formatting on it like:

>>> str(my_dict)[1:-1].replace(": ", ":").replace("'", "")
'2:9, 7:60, 6:90'

Answer 2

You can use ast.literal_eval and put brackets at each end of the string although your keys will be ints not strings.

from ast import literal_eval

Input  = "2:9, 6:90, 7:60"

Output = literal_eval(f"{{{input}}}")

---

{2: 9, 6: 90, 7: 60}

To fix the output to be string keys just convert them by hand

Output = dict(zip(map(str, Output), Output.values()))

---

{'2': 9, '7': 60, '6': 90}

---

Without importing any libraries you would need to use str.split

Output = dict(s.split(':') for s in Input.split(', '))

---

{'2': '9', '6': '90', '7': '60'}

Although now your values are strings so you'd need to fix that.

Output = dict(zip(Output, map(int, Output.values())))

---

{'2': 9, '7': 60, '6': 90}

Answer 3

Well without asking questions, if you want a one liner that makes the key a string and the value an int:

dict([[j[0].strip(), int(j[1])] for j in [i.split(':') for i in Input.split(',')]])