[Sync Iteration] python/matching-brackets/2

Author: exercism-solutions-syncer[bot]

solutions/python/matching-brackets/2/matching_brackets.py

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+"""
+Matching Brackets.
+
+You're given the opportunity to write software for the Bracketeer™,
+an ancient but powerful mainframe. The software that runs on it is
+written in a proprietary language. Much of its syntax is familiar,
+but you notice lots of brackets, braces and parentheses. Despite
+the Bracketeer™ being powerful, it lacks flexibility. If the source
+code has any unbalanced brackets, braces or parentheses, the Bracketeer™
+crashes and must be rebooted. To avoid such a scenario, you start writing
+code that can verify that brackets, braces, and parentheses are balanced
+before attempting to run it on the Bracketeer™.
+"""
+
+LEFT: str = "[{("
+RIGHT: str = "]})"
+PAIRS: dict = {
+    "[": "]",
+    "{": "}",
+    "(": ")",
+}
+
+
+def is_paired(input_string: str) -> bool:
+    """
+    Verify that any and all pairs of brackets are matched.
+
+    Given a string containing brackets [], braces {}, parentheses (),
+    or any combination thereof, verify that any and all pairs are matched
+    and nested correctly. Any other characters should be ignored. For example,
+    "{what is (42)}?" is balanced and "[text}" is not.
+
+    :param input_string:
+    :return:
+    """
+    # Empty string
+    if not input_string:
+        return True
+
+    # Remove all non bracket items and convert a string to a list.
+    brackets_list: list = [bracket for bracket in input_string if bracket in "(){}[]"]
+
+    # Odd number of brackets
+    if len(brackets_list) % 2 != 0:
+        return False
+
+    paired: bool = True
+    while paired and brackets_list:
+        for i, bracket in enumerate(brackets_list):
+            # Right side bracket found
+            if bracket in RIGHT:
+                paired = False
+                break
+
+            # No matching pair found
+            if (
+                brackets_list[i + 1] != PAIRS[bracket]
+                and brackets_list[-1] != PAIRS[bracket]
+            ):
+                paired = False
+                break
+
+            # Matching pair found next to it
+            if brackets_list[i + 1] == PAIRS[bracket]:
+                del brackets_list[1]
+                del brackets_list[0]
+                break
+
+            # Matching pair found at the end of the list
+            if brackets_list[-1] == PAIRS[bracket]:
+                del brackets_list[0]
+                del brackets_list[-1]
+                break
+
+    return paired