如何拆分括号内用逗号分隔的字符串

Question

I'm trying to split a string separated withing a bracket

for example, I have this string:

2021_02_25_{1,2,3,4}_stackoverflow

I want to extract the string inside the brackets {} and then split it by comma so the output would be:

[1, 2, 3, 4]

Answer 1

Use String's find method:

In [68]: s = '2021_02_25_{1,2,3,4}_stackoverflow'

In [75]: s[s.find("{")+1:s.find("}")].split(',')
Out[75]: ['1', '2', '3', '4']

If you want an integer list :

In [77]: list(map(int, s[s.find("{")+1:s.find("}")].split(',')))
Out[77]: [1, 2, 3, 4]

Answer 2

We can use re.findall here:

inp = "2021_02_25_{1,2,3,4}_stackoverflow"
matches = re.findall(r'\{(.*?)\}', inp)
output = [x.split(',') for x in matches]
print(output)  # [['1', '2', '3', '4']]

Note that this answer is robust to there possibly being more than one {...} term in the input string. If not, then just access the first element of the 2D list output above to get your answer.

Answer 3

You can try regular expression

import re

s = '2021_02_25_{1,2,3,4}_stackoverflow'
output = [int(i) for i in re.findall(r'{(\d(?:,\d)+)}', s)[0].split(',')]

print(output)

[1, 2, 3, 4]