Added Boolean operators and lowered line lengths

Added Bool operators and and or, and lowered some line lengths.  Also shifted some notes above the code lines to keep with same style and help readability.  Also added a note on list comprehension.  Also added adding to dictionary.

python3.html.markdown

@@ -61,6 +61,17 @@ False
 not True  # => False
 not False  # => True
 
+# Boolean Operators
+# Note "and" and "or" are case-sensitive
+True and False #=> False
+False or True #=> True
+
+# Note with ints
+0 and 2 #=> 0
+-5 or 0 #=> -5
+0 == False #=> True 
+2 == True #=> False #only 1 == True #=> True
+
 # Equality is ==
 1 == 1  # => True
 2 == 1  # => False
@@ -127,7 +138,8 @@ bool({}) #=> False
 # Python has a print function
 print("I'm Python. Nice to meet you!")
 
-# No need to declare variables before assigning to them. Convention is to use lower_case_with_underscores
+# No need to declare variables before assigning to them. 
+# Convention is to use lower_case_with_underscores
 some_var = 5
 some_var  # => 5
 
@@ -176,7 +188,8 @@ li[::-1]   # => [3, 4, 2, 1]
 del li[2]   # li is now [1, 2, 3]
 
 # You can add lists
-li + other_li   # => [1, 2, 3, 4, 5, 6] - Note: values for li and for other_li are not modified.
+# Note: values for li and for other_li are not modified.
+li + other_li   # => [1, 2, 3, 4, 5, 6] 
 
 # Concatenate lists with "extend()"
 li.extend(other_li)   # Now li is [1, 2, 3, 4, 5, 6]
@@ -215,14 +228,17 @@ filled_dict = {"one": 1, "two": 2, "three": 3}
 # Look up values with []
 filled_dict["one"]   # => 1
 
-# Get all keys as a list with "keys()". We need to wrap the call in list() because we are getting back an iterable. We'll talk about those later.
-list(filled_dict.keys())   # => ["three", "two", "one"]
+# Get all keys as a list with "keys()". 
+# We need to wrap the call in list() because we are getting back an iterable. We'll talk about those later.
 # Note - Dictionary key ordering is not guaranteed.
 # Your results might not match this exactly.
+list(filled_dict.keys())   # => ["three", "two", "one"]
+
 
 # Get all values as a list with "values()". Once again we need to wrap it in list() to get it out of the iterable.
-list(filled_dict.values())   # => [3, 2, 1]
 # Note - Same as above regarding key ordering.
+list(filled_dict.values())   # => [3, 2, 1]
+
 
 # Check for existence of keys in a dictionary with "in"
 "one" in filled_dict   # => True
@@ -242,6 +258,10 @@ filled_dict.get("four", 4)   # => 4
 filled_dict.setdefault("five", 5)  # filled_dict["five"] is set to 5
 filled_dict.setdefault("five", 6)  # filled_dict["five"] is still 5
 
+# Adding to a dictionary
+filled_dict.update({"four":4}) #=> {"one": 1, "two": 2, "three": 3, "four": 4}
+#filled_dict["four"] = 4  #another way to add to dict
+
 # Remove keys from a dictionary with del
 del filled_dict["one"]  # Removes the key "one" from filled dict
 
@@ -458,6 +478,7 @@ map(add_10, [1, 2, 3])   # => [11, 12, 13]
 filter(lambda x: x > 5, [3, 4, 5, 6, 7])   # => [6, 7]
 
 # We can use list comprehensions for nice maps and filters
+# List comprehension stores the output as a list which can itself be a nested list
 [add_10(i) for i in [1, 2, 3]]  # => [11, 12, 13]
 [x for x in [3, 4, 5, 6, 7] if x > 5]   # => [6, 7]