diff --git a/OOP/dog.py b/OOP/dog.py
index 49ba9f5..bcce89e 100644
--- a/OOP/dog.py
+++ b/OOP/dog.py
@@ -16,6 +16,9 @@ def __init__(self, name, age):
         self.name = name
         self.age = age
 
+    def speak(self, sound):
+        return f"{self.name} says {sound}"
+
 
 # Instantiate the Dog object
 philo = Dog("Philo", 5)
@@ -27,3 +30,6 @@ def __init__(self, name, age):
 # Is Philo a mammal?
 if philo.species == "mammal":
     print(f"{philo.name} is a {philo.species}!")
+
+print(philo.speak("Woof Woof"))
+print(mikey.speak("Waf Waf"))
diff --git a/OOP/dog_inheritance.py b/OOP/dog_inheritance.py
deleted file mode 100644
index 41e56a2..0000000
--- a/OOP/dog_inheritance.py
+++ /dev/null
@@ -1,40 +0,0 @@
-# Parent class
-class Dog:
-
-    # Class attribute
-    species = 'mammal'
-
-    # Initializer / Instance attributes
-    def __init__(self, name, age):
-        self.name = name
-        self.age = age
-
-    # instance method
-    def description(self):
-        return "{} is {} years old".format(self.name, self.age)
-
-    # instance method
-    def speak(self, sound):
-        return "{} says {}".format(self.name, sound)
-
-
-# Child class (inherits from Dog class)
-class RussellTerrier(Dog):
-    def run(self, speed):
-        return "{} runs {}".format(self.name, speed)
-
-
-# Child class (inherits from Dog class)
-class Bulldog(Dog):
-    def run(self, speed):
-        return "{} runs {}".format(self.name, speed)
-
-
-# Child classes inherit attributes and
-# behaviors from the parent class
-jim = Bulldog("Jim", 12)
-print(jim.description())
-
-# Child classes have specific attributes
-# and behaviors as well
-print(jim.run("slowly"))
\ No newline at end of file
diff --git a/OOP/dog_sol.py b/OOP/dog_sol.py
deleted file mode 100644
index cf43ca6..0000000
--- a/OOP/dog_sol.py
+++ /dev/null
@@ -1,27 +0,0 @@
-## Solution to Exercise "The Oldest Dog"
-
-class Dog:
-
-    # Class Attribute
-    species = 'mammal'
-
-    # Initializer / Instance Attributes
-    def __init__(self, name, age):
-        self.name = name
-        self.age = age
-
-
-# Instantiate the Dog object
-jake = Dog("Jake", 7)
-doug = Dog("Doug", 4)
-william = Dog("William", 5)
-
-
-# Determine the oldest dog
-def get_biggest_number(*args):
-    return max(args)
-
-
-# Output
-print("The oldest dog is {} years old.".format(
-    get_biggest_number(jake.age, doug.age, william.age)))
\ No newline at end of file
diff --git a/OOP/encapsulation.py b/OOP/encapsulation.py
new file mode 100644
index 0000000..571f172
--- /dev/null
+++ b/OOP/encapsulation.py
@@ -0,0 +1,25 @@
+# Using OOP in Python, we can restrict access to methods and variables.
+# This prevents data from direct modification which is called encapsulation.
+# In Python, we denote private attributes using underscore as the prefix i.e single _ or double __.
+
+class Computer:
+
+    def __init__(self):
+        self.__maxprice = 900
+
+    def sell(self):
+        print("Selling Price: {}".format(self.__maxprice))
+
+    def setMaxPrice(self, price):
+        self.__maxprice = price
+
+c = Computer()
+c.sell()
+
+# change the price
+c.__maxprice = 1000
+c.sell()
+
+# using setter function
+c.setMaxPrice(1000)
+c.sell()
\ No newline at end of file
diff --git a/OOP/inheritance.py b/OOP/inheritance.py
new file mode 100644
index 0000000..999d770
--- /dev/null
+++ b/OOP/inheritance.py
@@ -0,0 +1,30 @@
+# parent class
+class Bird:
+    
+    def __init__(self):
+        print("Bird is ready")
+
+    def whoisThis(self):
+        print("Bird")
+
+    def swim(self):
+        print("Swim faster")
+
+# child class
+class Penguin(Bird):
+
+    def __init__(self):
+        # call super() function
+        super().__init__()
+        print("Penguin is ready")
+
+    def whoisThis(self):
+        print("Penguin")
+
+    def run(self):
+        print("Run faster")
+
+peggy = Penguin()
+peggy.whoisThis()
+peggy.swim()
+peggy.run()
\ No newline at end of file
diff --git a/OOP/polymorphism.py b/OOP/polymorphism.py
new file mode 100644
index 0000000..677c233
--- /dev/null
+++ b/OOP/polymorphism.py
@@ -0,0 +1,27 @@
+class Parrot:
+
+    def fly(self):
+        print("Parrot can fly")
+    
+    def swim(self):
+        print("Parrot can't swim")
+
+class Penguin:
+
+    def fly(self):
+        print("Penguin can't fly")
+    
+    def swim(self):
+        print("Penguin can swim")
+
+# common interface
+def flying_test(bird):
+    bird.fly()
+
+#instantiate objects
+blu = Parrot()
+peggy = Penguin()
+
+# passing the object
+flying_test(blu)
+flying_test(peggy)
\ No newline at end of file
diff --git a/exeption_logging/exeption_logging.py b/exeption_logging/exeption_logging.py
index c7b9704..e5ddaef 100644
--- a/exeption_logging/exeption_logging.py
+++ b/exeption_logging/exeption_logging.py
@@ -30,7 +30,7 @@
 
 ## Let's add more code , with differnt broken line
 # try:
-#     f = open('test.txt','r') # file open fixed
+#     # f = open('test.txt','r') # file open fixed
 #     var = bad_var # bad varibale
 # except FileNotFoundError as e: # add and show as e, print(e)
 #     print("Sorry this file isn't exist!")
@@ -38,6 +38,7 @@
 # except Exception as e: # add and show as e, print(e)
 #     print("Something went wrong!")
 #     print(e)
+#     print(type(e))
 
 ## Else block
 # try:
@@ -61,17 +62,17 @@
 
 ## Log module
 
-# import logging
+import logging
 
-# logging.basicConfig(filename='example.log',level=logging.DEBUG)
+logging.basicConfig(filename='example.log',level=logging.DEBUG)
 
-# try:
-#     f = open('test.txt','r')
-# except Exception as e:
-#     logging.error(e)
-# else:
-#     print(f.read())
-#     logging.info("end file {} manipulation".format(f.name))
-#     f.close()
-# finally:
-#     logging.info("from finally block of exception")
\ No newline at end of file
+try:
+    f = open('test_.txt','r')
+except Exception as e:
+    logging.error(e)
+else:
+    print(f.read())
+    logging.info("end file {} manipulation".format(f.name))
+    f.close()
+finally:
+    logging.info("from finally block of exception")
\ No newline at end of file
diff --git a/files_os_module/test2.txt b/files_os_module/test2.txt
new file mode 100644
index 0000000..8318c86
--- /dev/null
+++ b/files_os_module/test2.txt
@@ -0,0 +1 @@
+Test
\ No newline at end of file
diff --git a/files_os_module/working_with_files.py b/files_os_module/working_with_files.py
index 00dfc40..3d90e62 100644
--- a/files_os_module/working_with_files.py
+++ b/files_os_module/working_with_files.py
@@ -14,15 +14,15 @@
 # print(f.read())
 
 ## read and print whole file :
-# with open('test.txt','r') as f:
+# with open('C:\\Users\\lev\\Documents\\OpsGuru\\projects\\Devops-course\\devops-python\\files_os_module\\test.txt','r') as f:
 #     f_contents = f.read()
 #     print(f_contents)
 
 ## read and print line by line file:
 # with open('test.txt','r') as f:
-# with open('test.txt','r') as f:
+# with open('test.txt','r') as fa:
 #     # f_contents = f.readlines()
-#     f_contents = f.readlines()
+#     f_contents = fa.readlines()
 #     print(f_contents)
 
 ## read and print single line, first one every time we call function readline will read next line (copy and show)
@@ -39,9 +39,9 @@
 
 ## More control for reading , explanation of read buffer
 # with open('test.txt','r') as f:
-#     f_contents = f.read()
-    # f_contents = f.read(100) # copy and explain
-    # print(f_contents, end='')
+#     # f_contents = f.read()
+#     f_contents = f.read(100) # copy and explain
+#     print(f_contents, end='')
 
 ## More contr eol for big files with while and EOF condition in while loop, also f.tell() and f.seek()
 # with open('test.txt','r') as f:
@@ -88,7 +88,7 @@
 #  suppose you want to make a subfolder under your home folder: $HOMEPATH/python-project/project1/temp
 # folder_name = os.path.join(os.environ['HOMEPATH'],'python-project','project1','temp')
 # os.makedirs(folder_name)
-
+# class
 ## Walking throught directories and files :
 # for dirpath, dirname, filename in os.walk(os.environ['HOMEPATH']):
 #     print('Current path',dirpath)
diff --git a/function/functions.py b/function/functions.py
index 65fee51..1870d70 100644
--- a/function/functions.py
+++ b/function/functions.py
@@ -33,15 +33,15 @@
 #####
 
 # Function with args and kwargs
-# def student_info(*args, **kwargs):
-#     print(args)
-#     print(kwargs)
-# #
-# student_info('Math', 'Art', name='Jhon', age=22)
-# print ("---")
-# courses = ['Math', 'Art']
-# info = {'name':'Jhon', 'age':22}
+def student_info(*args, **kwargs):
+    print(args)
+    print(kwargs)
+#
+student_info('Math', 'Art', name='Jhon', age=22)
+print ("---")
+courses = ['Math', 'Art']
+info = {'name':'Jhon', 'age':22}
 
-# student_info(courses, info)
-# print ("---")
-# student_info(*courses, **info)
\ No newline at end of file
+student_info(courses, info)
+print ("---")
+student_info(*courses, **info)
\ No newline at end of file
diff --git a/generators/generator.py b/generators/generator.py
index e17749d..6b31be3 100644
--- a/generators/generator.py
+++ b/generators/generator.py
@@ -1,9 +1,9 @@
-# def square_numbers(nums):
+# def square_numbers(*nums):
 #     for i in nums:
 #         yield (i*i)
 
 
-# my_nums = square_numbers([1, 2, 3, 4, 5])
+# my_nums = square_numbers(*[1, 2, 3, 4, 5])
 
 
 # print(next(my_nums))
@@ -12,11 +12,23 @@
 # print(next(my_nums))
 # print(next(my_nums))
 
+##
+
+# my_nums = square_numbers(*[1, 2, 3, 4, 5])
 # for num in my_nums:
 #     print(num)
 
-# list comprehention advance
+## Generator expressions
 
 # my_nums = list(x*x for x in [1,2,3,4,5])
+# my_sum = sum([x*x for x in range(1,10)])
+
+# print (my_nums)
+# print (my_sum)
 
-# print (my_nums)
\ No newline at end of file
+# jobtext = '/administrator/ HTTP/1.1'
+# all_lines = (line for line in open('..\\scripts\\access.log', 'r') )
+# job = ( line for line in all_lines if line.find(jobtext) != -1)
+# print(next(job))
+# print(next(job))
+# print(next(job))
\ No newline at end of file
diff --git a/if_else_elif/if_then_2.py b/if_else_elif/if_then_2.py
index 16a5161..7d561fc 100644
--- a/if_else_elif/if_then_2.py
+++ b/if_else_elif/if_then_2.py
@@ -1,6 +1,9 @@
 # Prompt user to enter number / test if even or odd
 
 
+
+
+
 def main():
     number = int(input("Please enter an integer: "))
 
diff --git a/iterators/iterators.py b/iterators/iterators.py
new file mode 100644
index 0000000..b1d4ade
--- /dev/null
+++ b/iterators/iterators.py
@@ -0,0 +1,28 @@
+class Counter():
+    def __init__(self, low, high):
+        self.current = low
+        self.high = high
+
+    def __iter__(self):
+        'Returns itself as an iterator object'
+        return self
+
+    def __next__(self):
+        'Returns the next value till current is lower than high'
+        if self.current > self.high:
+            raise StopIteration
+        else:
+            self.current += 1
+            return self.current - 1
+##
+c = Counter(5,10)
+
+for i in c:
+    print(i, end=' ')
+print('\n')
+##
+c = Counter(5,6)
+
+print(next(c))
+print(next(c))
+# print(next(c))
diff --git a/modules/__pycache__/mymath.cpython-38.pyc b/modules/__pycache__/mymath.cpython-38.pyc
deleted file mode 100644
index e70db86..0000000
Binary files a/modules/__pycache__/mymath.cpython-38.pyc and /dev/null differ
diff --git a/scripts/words_count.py b/scripts/words_count.py
index 72af679..2acbabb 100644
--- a/scripts/words_count.py
+++ b/scripts/words_count.py
@@ -14,7 +14,7 @@ def print_dictionary(dic, file_name):
         print('{:>20} {:>20}'.format(key, dic[key]))
 
 def main():
-    # file_name = input("Please insert file name to work with: ")
+    file_name = input("Please insert file name to work with: ")
     alpha_statistic = {}
     with open(file_name,'r') as f:
         lines = f.readlines()
diff --git a/working_with_json/json_demo.py b/working_with_json/json_demo.py
index 1b2581f..8f28749 100644
--- a/working_with_json/json_demo.py
+++ b/working_with_json/json_demo.py
@@ -18,4 +18,7 @@
 ## Simple deserialization example
 with open("demo.json","r") as read_file:
     data = json.load(read_file)
-    print(data)
\ No newline at end of file
+    print(data)
+    print(type(data))
+
+