Fix code style issues with Black

Author: lint-action

3_advanced/chapter13/examples/vector.py

@@ -1,21 +1,24 @@
 class Vector:
-	"""
-	Constructor
- 
-	self: a reference to the object we are creating
-	vals: a list of integers which are the contents of our vector
-	"""
-	def __init__(self, vals):
-		self.vals = vals # Notice! We are using the keyword self to create a field or property (for Javascript users) 
-		print("Assigned values ", vals, " to vector.")
- 
-	"""
+    """
+    Constructor
+
+    self: a reference to the object we are creating
+    vals: a list of integers which are the contents of our vector
+    """
+
+    def __init__(self, vals):
+        self.vals = vals  # Notice! We are using the keyword self to create a field or property (for Javascript users)
+        print("Assigned values ", vals, " to vector.")
+
+    """
 	String Function
  
 	Converts the object to a string in readable format for programmers
 	"""
-	def __str__(self):
-		return str(self.vals) # Returns the contents of the vector
- 
+
+    def __str__(self):
+        return str(self.vals)  # Returns the contents of the vector
+
+
 vec = Vector([2, 3, 2])
-print(str(vec)) # [2, 3, 2]
+print(str(vec))  # [2, 3, 2]