From 27cfae8f52ff5a9daf2ab7b16d2f6aa21cac7605 Mon Sep 17 00:00:00 2001
From: Kathy <40347043+kc0813@users.noreply.github.com>
Date: Wed, 9 Feb 2022 20:16:40 -0500
Subject: [PATCH] chore(Python): add first in first out queue (#691)

---
 algorithms/Python/README.md            |  2 +
 algorithms/Python/queues/fifo-queue.py | 65 ++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)
 create mode 100644 algorithms/Python/queues/fifo-queue.py

diff --git a/algorithms/Python/README.md b/algorithms/Python/README.md
index 282dee29..da6ca875 100644
--- a/algorithms/Python/README.md
+++ b/algorithms/Python/README.md
@@ -69,3 +69,5 @@
 - [Binary Tree](trees/binary_tree.py)
 - [Binary Search Tree](trees/binary_search_tree.py)
 
+## Queues
+- [First in First out Queue](queues/fifo-queue.py)
\ No newline at end of file
diff --git a/algorithms/Python/queues/fifo-queue.py b/algorithms/Python/queues/fifo-queue.py
new file mode 100644
index 00000000..7ddf7ad1
--- /dev/null
+++ b/algorithms/Python/queues/fifo-queue.py
@@ -0,0 +1,65 @@
+class FIFOqueue:
+
+    def __init__(self, item = 0) -> None:
+        """
+        creates the FIFOqueue object given an item,
+        will default to 0 if no item is passed.
+
+        firstNum: any
+        """
+        self.arr = [item]
+        
+
+    def enqueue(self, n) -> None:
+        """
+        adds n to the end of the queue in O(1) time
+
+        n: Any
+        """
+        self.arr.append(n)
+
+    def dequeue(self):
+        """
+        removes the first element from the queue and returns it in O(1) time
+        """
+        return self.arr.pop(0)
+    
+    def front(self):
+        """
+        returns the first element of the queue in O(1) time
+        """
+        return self.arr[0]
+    
+    def rear(self):
+        """
+        returns the last element of the queue in O(1) time
+        """
+        return self.arr[-1]
+
+# main
+if __name__ == '__main__':
+    exampleFIFO = FIFOqueue(1)
+    # now our queue should look like [1] after initialization
+    print(f"queue after initialization: {exampleFIFO.arr}")
+
+    exampleFIFO.enqueue(5)
+    # now our queue should look like [1, 5]
+    print(f"queue after enqueueing 5: {exampleFIFO.arr}")
+
+    print(f"If we dequeue, we are removing {exampleFIFO.dequeue()} from the queue")
+    # now our queue should look like [5]
+    print(f"queue after dequeue: {exampleFIFO.arr}")
+
+    exampleFIFO.enqueue(7)
+    # now our queue should look like [5, 7]
+    print(f"queue after enqueueing 7: {exampleFIFO.arr}")
+
+    exampleFIFO.enqueue(8)
+    # now our queue should look like [5, 7, 8]
+    print(f"queue after enqueueing 8: {exampleFIFO.arr}")
+
+    # front
+    print(f"If we try looking at the front of the queue we get: {exampleFIFO.front()}")
+
+    #rear
+    print(f"If we try looking at the rear of the queue we get: {exampleFIFO.rear()}")
\ No newline at end of file