Balanced Parentheses Checker | Dataford Interview Questions

The City of Columbus 311 intake workflow receives expressions containing grouping symbols. Write a function that determines whether every parenthesis, bracket, and brace is correctly opened and closed in the proper order.

Ignore all characters that are not one of (, ), [, ], {, or }. An empty expression or an expression containing no delimiters is balanced.

Formal Specification

Implement is_balanced(expression), which accepts a string and returns a boolean. Return True when all delimiters are properly matched and nested, and False otherwise.

Constraints

0 <= len(expression) <= 10^5
The expression contains printable ASCII characters.
Delimiters may be nested to any depth allowed by the input size.
Matching is type-sensitive for parentheses, brackets, and braces.

Function Signature

def is_balanced(expression):

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