Create __init__.py

Initialising of a Stack Class, has three methods: is_empty, push and pop.

Author: theycallmemac

data_structures/Stacks/__init__.py

@@ -0,0 +1,23 @@
+classStack:
+
+def__init__(self):
+self.stack= []
+self.top=0
+
+defis_empty(self):
+returnself.top==0
+
+defpush(self, item):
+ifself.top<len(self.stack):
+self.stack[self.top] =item
+else:
+self.stack.append(item)
+
+self.top+=1
+
+defpop(self):
+ifself.is_empty():
+returnNone
+else:
+self.top-=1
+returnself.stack[self.top]