如何忽略括号中的嵌套括号之间的子字符串而提取括号之间的子字符串？

Question

I have a string:

phy = '(s1:0.6507212936,((s2:0.4186036213,s3:0.4186036213):0.1428084058,((s4:0.1429514535,s5:0.1429514535):0.1695879844,s6:0.3125394379):0.2488725892):0.08930926654);'

How can I extract only the substrings that are enclosed between brackets and that do not contain any brackets within each substring? So, from my example I require two outputs: "s2:0.4186036213,s3:0.4186036213" and "s4:0.1429514535,s5:0.1429514535".

Answer 1

You can use regular rexpressions :

import re

phy = '(s1:0.6507212936,((s2:0.4186036213,s3:0.4186036213):0.1428084058,((s4:0.1429514535,s5:0.1429514535):0.1695879844,s6:0.3125394379):0.2488725892):0.08930926654);'
re.findall(r'\(([^\(\)]*)\)', phy)
# ['s2:0.4186036213,s3:0.4186036213', 's4:0.1429514535,s5:0.1429514535']

This captures everything non-brackety enclosed in opening-closing brackets. It does not, however, validate correct nesting levels.

Answer 2

Try this:

from collections import defaultdict
bracket_dict = defaultdict(int)
bracket_dict_ ={
    '(':')',
    '{':'}',
    '[':']'
}
bracket_dict.update(bracket_dict_)
bracket_list = bracket_dict.keys()

phy = '(s1:0.6507212936,((s2:0.4186036213,s3:0.4186036213):0.1428084058,((s4:0.1429514535,s5:0.1429514535):0.1695879844,s6:0.3125394379):0.2488725892):0.08930926654);'
inner_items=[]
brackets = []
start_index = None

for i in range(len(phy)):
    if phy[i] in bracket_list:
        start_index = i
        brackets.append(phy[i])

    if brackets:
        if phy[i] == bracket_dict[brackets[-1]]:
            inner_items.append(phy[start_index+1 : i])
            brackets.append(phy[i])
print(inner_items)
#['s2:0.4186036213,s3:0.4186036213', 's4:0.1429514535,s5:0.1429514535']

Answer 3

Use regex:

import re

reg = re.compile(r'[(]([^()]+)[)]')

phy = '(s1:0.6507212936,((s2:0.4186036213,s3:0.4186036213):0.1428084058,((s4:0.1429514535,s5:0.1429514535):0.1695879844,s6:0.3125394379):0.2488725892):0.08930926654)'

print(reg.findall(phy))

Output :

C:\Users\Desktop>py x.py
['s2:0.4186036213,s3:0.4186036213', 's4:0.1429514535,s5:0.1429514535']