Add class, iterator, and generator.

Author: hermite2053

class/generator/main.py

@@ -0,0 +1,16 @@
+def reverse_str(str):
+    for ch in range(len(str)-1, -1, -1):
+        yield str[ch]
+
+    return str
+
+
+s = 'Python'
+print(s)
+for ch in reverse_str(s):
+    print(ch)
+
+t = 'semordnilap'
+print(t)
+for ch in reverse_str(t):
+    print(ch)

class/inheritance/main.py

@@ -0,0 +1,44 @@
+class two_num:
+    def __init__(self, i1, i2):
+        self.i1 = i1
+        self.i2 = i2
+
+
+    def sum(self):
+        return self.i1 + self.i2
+
+
+    def print_elm1(self):
+        print(self.i1)
+
+
+    def print_elm2(self):
+        print(self.i2)
+
+
+class three_num(two_num):
+    def __init__(self, i1, i2, i3):
+        self.i1 = i1
+        self.i2 = i2
+        self.i3 = i3
+
+
+    # override
+    def sum(self):
+        return self.i1 + self.i2 + self.i3
+
+
+    def print_elm3(self):
+        print(self.i3)
+
+
+a = two_num(2, 3)
+print(a.sum())
+a.print_elm1()
+a.print_elm2()
+
+b = three_num(10, 20, 30)
+print(b.sum())
+b.print_elm1()
+b.print_elm2()
+b.print_elm3()

class/instance/main.py

@@ -0,0 +1,50 @@
+class Currency:
+    def __init__(self, value, unit):
+        self.value = value
+        self.unit = unit
+        self.user = []
+
+
+    def add_user(self, user):
+        self.user.append(user)
+
+
+    def add_some_users(self, users):
+        for user in users:
+            self.user.append(user)
+
+
+    def add_currency(self, x):
+        self.value = self.value + x
+
+
+    def print_currency(self):
+        print(f'{self.value} {self.unit}')
+
+
+    def print_user(self):
+        print(self.user)
+
+
+European_Union = ['Austria', 'Belgium', 'Cyprus', 'Estonia', 'Finland',
+                'France', 'Germany', 'Greece', 'Ireland', 'Italy',
+                'Latvia', 'Lithuania', 'Luxembourg', 'Malta', 'Netherlands',
+                'Portugal', 'Slovakia', 'Slovenia', 'Spain']
+
+a = Currency(10, 'JPY')
+b = Currency(20, 'EUR')
+
+a.print_currency()
+b.print_currency()
+
+a.add_currency(100)
+b.add_currency(10)
+
+a.print_currency()
+b.print_currency()
+
+a.add_user('Japan')
+b.add_some_users(European_Union)
+
+a.print_user()
+b.print_user()

class/iterator/main.py

@@ -0,0 +1,15 @@
+v = [2, -4, 7]
+s = 'dragon'
+
+it_v = iter(v)
+print(next(it_v))
+print(next(it_v))
+print(next(it_v))
+
+it_s = iter(s)
+print(next(it_s))
+print(next(it_s))
+print(next(it_s))
+print(next(it_s))
+print(next(it_s))
+print(next(it_s))