added description for available datastructures

Author: phk

20_sets.py

@@ -1,11 +1,20 @@
-# python3 sets: introduced set literals and comprehensions (see PEP-3100) which allowed us to avoid intermediate lists
+# python3 datastructure sets: introduced set literals and comprehensions (see PEP-3100) which allowed us to avoid intermediate lists
 
 """
-Python3: List vs Tuple vs Set vs Dictionary
-Lists - for ordered sequence of indexed objects
-Tuple - can be considered as immutable/hashable list
-Python Set - unique list
-Python Dictionary / dict - pair of key and values
+[Python3: List vs Tuple vs Set vs Dictionary]
+
+Lists:  for ordered collection of items or sequence of objects,
+        indexed, _not_ hashable
+
+Tuples: can be considered as immutable list,
+        elements can't be added, removed or replaced after declaration,
+        hashable, _not_ indexed
+
+Sets:   unique list w/o order and duplicates,
+        fast + union/intersection operations/methods
+        not hashable
+
+Dict:   pair of key and values
 """
 
 # define set (note the missing colon on end of line)

21_dictionaries.py

@@ -1,11 +1,20 @@
-# python3 dictionaries:
+# python3 datastructure dictionaries:
 
 """
-Python3: List vs Tuple vs Set vs Dictionary
-Lists - for ordered sequence of indexed objects
-Tuple - can be considered as immutable/hashable list
-Python Set - unique list
-Python Dictionary / dict - pair of key and values
+[Python3: List vs Tuple vs Set vs Dictionary]
+
+Lists:  for ordered collection of items or sequence of objects,
+        indexed, _not_ hashable
+
+Tuples: can be considered as immutable list,
+        elements can't be added, removed or replaced after declaration,
+        hashable, _not_ indexed
+
+Sets:   unique list w/o order and duplicates,
+        fast + union/intersection operations/methods
+        not hashable
+
+Dict:   pair of key and values
 """
 
 # import some functions and classes [doesn't work if filenames start w/ numbers eg. 98_test]

23_tuples.py

@@ -1,9 +1,38 @@
-# python3 tuples: can be considered as immutable/hashable list
+# python3 datastructure tuples: can be considered as immutable/hashable list
 
 """
-Python3: List vs Tuple vs Set vs Dictionary
-Lists - for ordered sequence of indexed objects
-Tuple - can be considered as immutable/hashable list
-Python Set - unique list
-Python Dictionary / dict - pair of key and values
+[Python3: List vs Tuple vs Set vs Dictionary]
+
+Lists:  for ordered collection of items or sequence of objects,
+        indexed, _not_ hashable
+
+Tuples: can be considered as immutable list,
+        elements can't be added, removed or replaced after declaration,
+        hashable, _not_ indexed
+
+Sets:   unique list w/o order and duplicates,
+        fast + union/intersection operations/methods
+        not hashable
+
+Dict:   pair of key and values
 """
+
+# tuple declaration
+s1 = (1, 2, 3, 4, 1)
+s2 = ('jan','feb','mar','apr','may','june','july','aug','sep','oct','dec','jan')
+s3 = ('a', 0, 3.14)
+
+print(s1)
+print(type(s1))
+print(s2)
+print(type(s2))
+print(s3)
+print(type(s3))
+
+# operations: count() counts given element/object in tuple, index() gives index of given element/object in tuple
+print('print(s1.count(1))')
+print(s1.count(1))
+print("print(s2.count('jan'))")
+print(s2.count('feb'))
+print('print(s3.index(0))')
+print(s3.index('a'))

9_lists.py

@@ -1,11 +1,20 @@
-# python3 lists: ordered sequence of objects
+# python3 datastructure lists: ordered sequence of objects
 
 """
-Python3: List vs Tuple vs Set vs Dictionary
-Lists - for ordered sequence of indexed objects
-Tuple - can be considered as immutable/hashable list
-Python Set - unique list
-Python Dictionary / dict - pair of key and values
+[Python3: List vs Tuple vs Set vs Dictionary]
+
+Lists:  for ordered collection of items or sequence of objects,
+        indexed, _not_ hashable
+
+Tuples: can be considered as immutable list,
+        elements can't be added, removed or replaced after declaration,
+        hashable, _not_ indexed
+
+Sets:   unique list w/o order and duplicates,
+        fast + union/intersection operations/methods
+        not hashable
+
+Dict:   pair of key and values
 """
 
 # list indexes