code for dequeue

yashaswiadyalu · yashaswiadyalu · commit f05173438f63 · 2020-10-18T20:49:05.000+05:30
diff --git a/data-structures/dequeue.py b/data-structures/dequeue.py
@@ -0,0 +1,48 @@
+class Dequeue:
+    def __init__(self):
+        self.items = []
+ 
+    def is_empty(self):
+        return self.items == []
+ 
+    def append(self, data):
+        self.items.append(data)
+ 
+    def append_left(self, data):
+        self.items.insert(0, data)
+ 
+    def pop(self):
+        return self.items.pop()
+ 
+    def pop_left(self):
+        return self.items.pop(0)
+ 
+ 
+q = Dequeue()
+print('Menu')
+print('append <value>')
+print('appendleft <value>')
+print('pop')
+print('popleft')
+print('quit')
+ 
+while True:
+    do = input('What would you like to do? ').split()
+ 
+    operation = do[0].strip().lower()
+    if operation == 'append':
+        q.append(int(do[1]))
+    elif operation == 'appendleft':
+        q.append_left(int(do[1]))
+    elif operation == 'pop':
+        if q.is_empty():
+            print('Dequeue is empty.')
+        else:
+            print('Popped value from right: ', q.pop())
+    elif operation == 'popleft':
+        if q.is_empty():
+            print('Dequeue is empty.')
+        else:
+            print('Popped value from left: ', q.pop_left())
+    elif operation == 'quit':
+        break
