From 6e408fae4e8c59f40b4f78b17753f7afa84e5a09 Mon Sep 17 00:00:00 2001
From: Dominic <domyoung424@gmail.com>
Date: Fri, 5 Oct 2018 11:55:14 -0500
Subject: [PATCH] implement balanced brackets in python

---
 Python/balanced-brackets.py | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 Python/balanced-brackets.py

diff --git a/Python/balanced-brackets.py b/Python/balanced-brackets.py
new file mode 100644
index 000000000..74cc3ffe5
--- /dev/null
+++ b/Python/balanced-brackets.py
@@ -0,0 +1,21 @@
+PAIRINGS = {
+    '(': ')',
+    '{': '}',
+    '[': ']'
+}
+
+
+def is_balanced(symbols):
+    stack = []
+    for s in symbols:
+        if s in PAIRINGS.keys():
+            stack.append(s)
+        else:
+            try:
+                expected_opening_symbol = stack.pop()
+            except IndexError:  # too many closing symbols
+                return False
+            if s != PAIRINGS[expected_opening_symbol]:  # mismatch
+                return False
+    return len(stack) == 0  # false if too many opening symbols
+