Reverted changes

 - stack.py, binary_search.py, depth_first_search.py

Signed-off-by: IanDoarn <[email protected]>

Author: IanDoarn

pygorithm/data_structures/stack.py

@@ -127,8 +127,7 @@ def infix_to_postfix(self):
                     postfix.append(top_operator)
                     top_operator = self.my_stack.pop()
             else:
-                while not self.my_stack.is_empty() \
-                        and self.__precedence(self.expression[i] <= self.__precedence(self.my_stack.peek())):
+                while not self.my_stack.is_empty() and self.__precedence(self.expression[i] <= self.__precedence(self.my_stack.peek())):
                     postfix.append(self.my_stack.pop())
                 self.my_stack.push(self.expression[i])
 

pygorithm/searching/binary_search.py

@@ -29,16 +29,19 @@ def search(_list, target):
     # Last position of the list
     right = len(_list) - 1
 
-    # you can also write while True condition
-    while left <= right:
-        mid = (left + right) // 2
-        if target == _list[mid]:
-            return mid
-        elif target < _list[mid]:
-            right = mid - 1
-        else:
-            left = mid + 1
-    return False
+    try:
+        # you can also write while True condition
+        while left <= right:
+            mid = (left + right) // 2
+            if target == _list[mid]:
+                return mid
+            elif target < _list[mid]:
+                right = mid - 1
+            else:
+                left = mid + 1
+        return False
+    except TypeError:
+        return False
 
 
 # TODO: Are these necessary?

pygorithm/searching/depth_first_search.py

@@ -5,7 +5,7 @@
 import inspect
 
 
-def search(graph, start, path=None):
+def search(graph, start, path=[]):
     """
     depth first search algorithm
 
@@ -18,11 +18,11 @@ def search(graph, start, path=None):
     if start not in graph or graph[start] is None or graph[start] == []:
         return path
 
-    _path = path + [start]
+    path = path + [start]
     for edge in graph[start]:
-        if edge not in _path:
-            _path = search(graph, edge, _path)
-    return _path
+        if edge not in path:
+            path = search(graph, edge, path)
+    return path
 
 
 # TODO: Are these necessary?