diff --git a/ciphers/playfair_cipher.py b/ciphers/playfair_cipher.py
index 8ef09160d..20449b161 100644
--- a/ciphers/playfair_cipher.py
+++ b/ciphers/playfair_cipher.py
@@ -13,8 +13,8 @@ def chunker(seq, size):
 
 def prepare_input(dirty):
     """
-    Prepare the plaintext by uppcasing it 
-    and seperating repeated letters with X's
+    Prepare the plaintext by up-casing it
+    and separating repeated letters with X's
     """
     
     dirty = ''.join([c.upper() for c in dirty if c in string.ascii_letters])
@@ -38,7 +38,7 @@ def prepare_input(dirty):
 
 def generate_table(key):
 
-    # I and J are used interchangably to allow
+    # I and J are used interchangeably to allow
     # us to use a 5x5 table (25 letters)
     alphabet = "ABCDEFGHIKLMNOPQRSTUVWXYZ"
     # we're using a list instead of a '2d' array because it makes the math 
diff --git a/data_structures/AVL/AVL.py b/data_structures/AVL/AVL.py
index 84f79fd1c..d01e8f825 100644
--- a/data_structures/AVL/AVL.py
+++ b/data_structures/AVL/AVL.py
@@ -1,6 +1,6 @@
-'''
-A AVL tree
-'''
+"""
+An AVL tree
+"""
 from __future__ import print_function
 
 
@@ -101,10 +101,10 @@ class AVL:
                 if height_left > height_right:
                     left_child = n.left
                     if left_child is not None:
-                        h_right = (right_child.right.height
-                                    if (right_child.right is not None) else 0)
-                        h_left = (right_child.left.height
-                                    if (right_child.left is not None) else 0)
+                        h_right = (left_child.right.height
+                                    if (left_child.right is not None) else 0)
+                        h_left = (left_child.left.height
+                                    if (left_child.left is not None) else 0)
                     if (h_left > h_right):
                         self.rotate_left(n)
                         break
diff --git a/data_structures/Arrays b/data_structures/Arrays
index 03eaefac1..e2c1243f5 100644
--- a/data_structures/Arrays
+++ b/data_structures/Arrays
@@ -1 +1 @@
-Arrays implimentation using python programming.
+Arrays implementation using python programming.
diff --git a/data_structures/Graph/BellmanFord.py b/data_structures/Graph/BellmanFord.py
index b9207c422..82db80546 100644
--- a/data_structures/Graph/BellmanFord.py
+++ b/data_structures/Graph/BellmanFord.py
@@ -7,11 +7,11 @@ def printDist(dist, V):
 			print(i,"\t",int(dist[i]),end = "\t")
 		else:
 			print(i,"\t","INF",end="\t")
-		print();
+		print()
 
 def BellmanFord(graph, V, E, src):
 	mdist=[float('inf') for i in range(V)]
-	mdist[src] = 0.0;
+	mdist[src] = 0.0
 	
 	for i in range(V-1):
 		for j in range(V):
@@ -35,13 +35,13 @@ def BellmanFord(graph, V, E, src):
 			
 
 #MAIN
-V = int(input("Enter number of vertices: "));
-E = int(input("Enter number of edges: "));
+V = int(input("Enter number of vertices: "))
+E = int(input("Enter number of edges: "))
 
 graph = [dict() for j in range(E)]
 
 for i in range(V):
-	graph[i][i] = 0.0;
+	graph[i][i] = 0.0
 
 for i in range(E):
 	print("\nEdge ",i+1)
diff --git a/data_structures/Graph/Dijkstra.py b/data_structures/Graph/Dijkstra.py
index ae6a1a283..891717141 100644
--- a/data_structures/Graph/Dijkstra.py
+++ b/data_structures/Graph/Dijkstra.py
@@ -7,7 +7,7 @@ def printDist(dist, V):
 			print(i,"\t",int(dist[i]),end = "\t")
 		else:
 			print(i,"\t","INF",end="\t")
-		print();
+		print()
 
 def minDist(mdist, vset, V):
 	minVal = float('inf')
@@ -25,7 +25,7 @@ def Dijkstra(graph, V, src):
 	
 	for i in range(V-1):
 		u = minDist(mdist, vset, V)
-		vset[u] = True;
+		vset[u] = True
 		
 		for v in range(V):
 			if (not vset[v]) and graph[u][v]!=float('inf') and mdist[u] + graph[u][v] < mdist[v]:
@@ -38,20 +38,20 @@ def Dijkstra(graph, V, src):
 			
 
 #MAIN
-V = int(input("Enter number of vertices: "));
-E = int(input("Enter number of edges: "));
+V = int(input("Enter number of vertices: "))
+E = int(input("Enter number of edges: "))
 
 graph = [[float('inf') for i in range(V)] for j in range(V)]
 
 for i in range(V):
-	graph[i][i] = 0.0;
+	graph[i][i] = 0.0
 
 for i in range(E):
 	print("\nEdge ",i+1)
 	src = int(input("Enter source:"))
 	dst = int(input("Enter destination:"))
 	weight = float(input("Enter weight:"))
-	graph[src][dst] = weight;
+	graph[src][dst] = weight
 
 gsrc = int(input("\nEnter shortest path source:"))
 Dijkstra(graph, V, gsrc)
diff --git a/dynamic_programming/FloydWarshall.py b/dynamic_programming/FloydWarshall.py
index bf7714124..038499ca0 100644
--- a/dynamic_programming/FloydWarshall.py
+++ b/dynamic_programming/FloydWarshall.py
@@ -8,7 +8,7 @@ class Graph:
         self.dp = [[math.inf for j in range(0,N)] for i in range(0,N)] # dp[i][j] stores minimum distance from i to j
 
     def addEdge(self, u, v, w):
-        self.dp[u][v] = w;
+        self.dp[u][v] = w
 
     def floyd_warshall(self):
         for k in range(0,self.N):