Python: Find a valid substring of s that contains matching brackets, at least one of which is nested

Python Programming Puzzles: Exercise-87 with Solution

Write a Python program to find a valid substring of a given string that contains matching brackets, at least one of which is nested.

Input: 
 ]][][[]]] 

Output:
[[]]

Input:  
]]]]]]]]]]]]]]]]][][][][]]]]]]]]]]][[[][[][[[[[][][][]][[[[[[[[[[[[[[[[[[ 

Output:
[[][][][]]
 

Pictorial Presentation:

Sample Solution:

Python Code:

#License: https://bit.ly/3oLErEI

def test(s):
    import re
    return re.search(r"\[(\[\])+\]", s).group(0)

brackets = "]][][[]]]"
print("Original List of strings:",brackets)
print("\nFind a valid substring of the said string that contains matching brackets, at least one of which is nested:")
print(test(brackets))
brackets = "]]]]]]]]]]]]]]]]][][][][]]]]]]]]]]][[[][[][[[[[][][][]][[[[[[[[[[[[[[[[[["
print("\nOriginal List of strings:",brackets)
print("\nFind a valid substring of the said string that contains matching brackets, at least one of which is nested:")
print(test(brackets)) 

Sample Output:

Original List of strings: ]][][[]]]

Find a valid substring of the said string that contains matching brackets, at least one of which is nested:
[[]]

Original List of strings: ]]]]]]]]]]]]]]]]][][][][]]]]]]]]]]][[[][[][[[[[][][][]][[[[[[[[[[[[[[[[[[

Find a valid substring of the said string that contains matching brackets, at least one of which is nested:
[[][][][]]

Flowchart:

Python Code Editor :

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