from decimal import Decimal a = Decimal('1.1') print(type(a),a) b = Decimal('0.5') c = Decimal('0.4') print(b-c) d = Decimal('0.1') print(0.1 * 3) print(d * 3) _1 = 2 #comment y = 2 print(id(y)) y = y + 12 print(_1,y) print(id(_1),id(y)) x = 1 print(type(x), id(x)) x = float(x) print(type(x), id(x)) x = True print(type(x), id(x)) print(1 == True) print(0 != False) print(1/3 + 1/3 + 1/3) print(1, 5j) name = ['John','Amy', 'Peter', [True, 12, 55, ["hello", "world", 3.4, '1'], "Dave"]] print(name) print(name[0], id(name[0]), name[1], id(name[1]), name[2], id(name[2])) age = [30,12,60] name[1] = age print(name, name[1], name[1][1]) print(name[3][3][3]) a = 1 print(id(a)) a = 10 print(id(a)) x = ["john", "ann"] print(id(x),x) x[0] = ["john", "ann", "peter"] print(id(x),x) y = x # x address insert to y. Therefore, y addess equal to x address print(id(y),y) x = [] print(id(x)) # The id of x (Line 47) is different with x (Line 49) x = ["john", "ann", "peter"] print(id(x)) x = ["john", "ann", "peter"] print(id(x)) b = "abcdefghijklmnopq" c = "abcdefghijklmnopq" print(id(b)) print(id(c)) a = {1,2,3,4,5,6,1,1,2,2,3,4,2,3,1} print(a) a = {'apple',1,"dog",2,3,"apple",4,5,6,"dog",1,1,2,2,3,4,2,3,1} print(a) # The result is random. # frozenset -> don't let anyone edit the list. if a(frozenset)|b, result is frozenset. if a(normalset)|b(frozenset), result is normalset. #a = frozenset({'apple',1,"dog",2,3,"apple",4,5,6,"dog",1,1,2,2,3,4,2,3,1}) x = 1 a = {'apple',1,"dog",2,3,"apple",4,5,6,"dog",1,1,2,2,3,4,2,3,1,print(x),} #If python see (), it will handle () firstly. In this case, it will print '1' firstly. b = frozenset({'cat',7,8,1,2}) union = a | b print("Union:") print(union) intersection = a & b print("intersection:") print(intersection) intersection.remove(1) print(intersection) union.remove(1) print(union)