🏣 Clean up for arxiv

book/ebook_src/builtin_structures/balance_symbols.py

@@ -0,0 +1,40 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+'''
+Given a N different open and close braces in a string "( { [ } ] )".
+How do you check whether the string has matching braces.
+'''
+
+from collections import Counter
+def check_if_balance(string):
+    '''
+    >>> check_if_balance('{[[(])}]')
+    True
+    >>> check_if_balance('{[[()}]')
+    False
+    >>> check_if_balance('')
+    True
+    '''
+    table = Counter()
+    for i in string:
+
+        index = str(ord(i))[0]
+        if i in '{[(':
+            table[index] += 1
+
+        elif i in ')}]':
+            table[index] -= 1
+
+    for i in table.values():
+        if i !=-0:
+            return False
+    return True
+
+
+
+if __name__ == '__main__':
+    import doctest
+    doctest.testmod()
+