Add itertools module examples

Author: DevCTx

useful_samples/itertools_module.py

@@ -1,20 +1,52 @@
+'''
+    Itertools module : returns iterators on
+    - combinations : Associate 2 items of the list
+    - permutations : Associate 2 items of the list and their permutations
+    - combinations_with_replacement : Associate 2 items of the list and the doubled items
+    - product : Associate 2 items of the list, their permutations and the doubled items
+'''
 from itertools import combinations, permutations, combinations_with_replacement, product
 
-# Combinations : Associate 2 items of the list
-print( f"{[x+y for (x,y) in combinations('ABCD', 2)] = }" )
-# ['AB', 'AC', 'AD', 'BC', 'BD', 'CD']
+obj_list = [1,2,3,4]
+print("\nworks on lists :", obj_list)
+print( f"{[i for i in combinations(obj_list, 2)] = }" )
+# [(1, 2), (1, 3), (1, 4), (2, 3), (2, 4), (3, 4)]
+print( f"{[i for i in permutations(obj_list, 2)] = }" )
+# [(1, 2), (1, 3), (1, 4), (2, 1), (2, 3), (2, 4), (3, 1), (3, 2), (3, 4), (4, 1), (4, 2), (4, 3)]
+print( f"{[i for i in combinations_with_replacement(obj_list,2)] = }" )
+# [(1, 1), (1, 2), (1, 3), (1, 4), (2, 2), (2, 3), (2, 4), (3, 3), (3, 4), (4, 4)]
+print( f"{[i for i in product(obj_list, repeat=2)] = }" )
+# [(1, 1), (1, 2), (1, 3), (1, 4), (2, 1), (2, 2), (2, 3), (2, 4), (3, 1), (3, 2), (3, 3), (3, 4), (4, 1), (4, 2), (4, 3), (4, 4)]
 
-# Permutations : Associate 2 items of the list and their permutations
-print( f"{[x+y for (x,y) in permutations('ABCD', 2)] = }" )
-# ['AB', 'AC', 'AD', 'BA', 'BC', 'BD', 'CA', 'CB', 'CD', 'DA', 'DB', 'DC']
+obj_list = (1,2,3,4)
+print("\nworks on tuples :", obj_list)                      # Same results than list
+print( f"{[i for i in combinations(obj_list, 2)] = }" )
+# [(1, 2), (1, 3), (1, 4), (2, 3), (2, 4), (3, 4)]
+print( f"{[i for i in permutations(obj_list, 2)] = }" )
+# [(1, 2), (1, 3), (1, 4), (2, 1), (2, 3), (2, 4), (3, 1), (3, 2), (3, 4), (4, 1), (4, 2), (4, 3)]
+print( f"{[i for i in combinations_with_replacement(obj_list,2)] = }" )
+# [(1, 1), (1, 2), (1, 3), (1, 4), (2, 2), (2, 3), (2, 4), (3, 3), (3, 4), (4, 4)]
+print( f"{[i for i in product(obj_list, repeat=2)] = }" )
+# [(1, 1), (1, 2), (1, 3), (1, 4), (2, 1), (2, 2), (2, 3), (2, 4), (3, 1), (3, 2), (3, 3), (3, 4), (4, 1), (4, 2), (4, 3), (4, 4)]
 
-# Combinations : Associate 2 items of the list and the doubled items
-print( f"{[x+y for (x,y) in combinations_with_replacement('ABCD',2)] = }" )
+obj_list = 'ABCD'
+print("\nworks on string :", obj_list)
+print( f"{[x+y for (x,y) in combinations(obj_list, 2)] = }" )
+# ['AB', 'AC', 'AD', 'BC', 'BD', 'CD']
+print( f"{[x+y for (x,y) in permutations(obj_list, 2)] = }" )
+# ['AB', 'AC', 'AD', 'BA', 'BC', 'BD', 'CA', 'CB', 'CD', 'DA', 'DB', 'DC']
+print( f"{[x+y for (x,y) in combinations_with_replacement(obj_list,2)] = }" )
 # ['AA', 'AB', 'AC', 'AD', 'BB', 'BC', 'BD', 'CC', 'CD', 'DD']
-
-# Product : Associate 2 items of the list, their permutations and the doubled items
-print( f"{[x+y for (x,y) in product('ABCD', repeat=2)] = }" )
+print( f"{[x+y for (x,y) in product(obj_list, repeat=2)] = }" )
 # ['AA', 'AB', 'AC', 'AD', 'BA', 'BB', 'BC', 'BD', 'CA', 'CB', 'CC', 'CD', 'DA', 'DB', 'DC', 'DD']
 
-
-
+obj_list = 'TTST'
+print("\nand doesn't take care of duplicates :", obj_list)
+print( f"{[x+y for (x,y) in combinations(obj_list, 2)] = }" )
+# ['AB', 'AC', 'AD', 'BC', 'BD', 'CD']
+print( f"{[x+y for (x,y) in permutations(obj_list, 2)] = }" )
+# ['AB', 'AC', 'AD', 'BA', 'BC', 'BD', 'CA', 'CB', 'CD', 'DA', 'DB', 'DC']
+print( f"{[x+y for (x,y) in combinations_with_replacement(obj_list,2)] = }" )
+# ['AA', 'AB', 'AC', 'AD', 'BB', 'BC', 'BD', 'CC', 'CD', 'DD']
+print( f"{[x+y for (x,y) in product(obj_list, repeat=2)] = }" )
+# ['AA', 'AB', 'AC', 'AD', 'BA', 'BB', 'BC', 'BD', 'CA', 'CB', 'CC', 'CD', 'DA', 'DB', 'DC', 'DD']