programiz · parewa-ranjit · Sep 30, 2020 · Sep 30, 2020
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+.idea/
diff --git a/11-pass.md b/11-pass.md
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 # Python `pass`
 
-**Video link:** 
+**Video link:** [https://youtu.be/n4B3zYfk_Pg](https://youtu.be/n4B3zYfk_Pg)
 
 In this video, we learned about the `pass` statement in Python.
 

diff --git a/12-function.md b/12-function.md
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+# Python Functions
+
+**Video link:** 
+
+In this video, we learned about Python functions that make our program more organized and manageable by dividing our code into smaller and modular chunks.
+
+**Programs in the Video**
+
+- [Python Functions](#python-functions-1)
+- [Function Arguments](#function-arguments)
+- [Passing Multiple Arguments](#passing-multiple-arguments)
+- [Return Value from Function](#return-value-from-function)
+- [**Example**: Grading Students](#example)
+- [**Task**: Function to Add and Multiply](#programming-task)
+
+---
+## Python Functions
+A function is a group of related statements that performs a specific task.
+
+For example,
+
+```python
+def greet():
+    print("Hello")
+    print("How do you do?")
+```
+Here, we have defined a function named `greet`.
+
+To create a function, we use the `def` keyword followed by the function name, parenthesis `()`, and a colon `:`.
+The body of the function is specified using indentation.
+
+When we run the program, we don't see any output.
+
+It is because defining a function won't do anything. To bring the function into action, we need to call it.
+
+```python
+def greet():
+    print("Hello")
+    print("How do you do?")
+
+greet()
+```
+
+**Output**
+
+```
+Hello
+How do you do?
+```
+
+One advantage of defining a function is that we can call it any number of times.
+
+```python
+def greet():
+    print("Hello")
+    print("How do you do?")
+
+greet()
+greet()
+greet()
+```
+
+**Output**
+
+```
+Hello
+How do you do?
+Hello
+How do you do?
+Hello
+How do you do?
+```
+
+Also, we need to define a function first before we can call it.
+
+The following code gives an error:
+
+```python
+# function call
+greet()
+
+# function definition
+def greet():
+    print("Hello")
+    print("How do you do?")
+```
+
+When the `greet()` function is called, Python doesn't know that this function exists because it's defined after the function call.
+
+---
+
+## Function Arguments
+
+Suppose we want to make our `greet()` function a bit more personal.
+
+Instead of printing `Hello`, we want to print something like `Hello Jack` or whatever the person's name is.
+
+For this, we can use function arguments:
+
+```python
+def greet(name):
+    print("Hello", name)
+    print("How do you do?")
+
+greet("Jack")
+```
+**Output**
+
+```
+Hello Jack
+How do you do?
+```
+
+Function arguments are passed inside the parenthesis during the function call.
+
+It can then be accessed using the `name` parameter in the function definition.
+
+---
+
+## Passing Multiple Arguments
+
+If we need to pass multiple arguments to a function, we can separate them by commas.
+
+Let's create a function to add two numbers.
+
+```python
+def add_numbers(n1, n2):
+    result = n1 + n2
+    print("The sum is", result)
+
+
+number1 = 5.4
+number2 = 6.7
+add_numbers(number1, number2)
+
+```
+
+**Output**
+
+```
+The sum is 12.100000000000001
+```
+We have passed `number1` and `number2` as arguments to the `add_numbers()` function.
+These arguments are accepted as `n1` and `n2` once they are passed to the `add_numbers()` function.
+
+>**Note:** We get this number instead of 12.1 because of floating-point representation error in Python.
+
+---
+
+## Return Value from Function
+
+```python
+def add_numbers(n1, n2):
+    result = n1 + n2
+    print("The sum is", result)
+
+
+add_numbers(5.4, 6.7)
+```
+Sometimes it's better just to find the sum inside the function and print the result somewhere else.
+
+We can achieve that by using the `return` statement.
+
+```python
+def add_numbers(n1, n2):
+    result = n1 + n2
+    return result
+
+result = add_numbers(5.4, 6.7)
+print("The sum is", result)
+```
+
+**Output**
+
+```
+The sum is 12.100000000000001
+```
+
+---
+
+## Types of functions
+
+There are two types of functions:
+
+- **Built-in functions** - Functions that are built into Python.
+- **User-defined functions** - Functions defined by the users themselves.
+
+Some built-in functions:
+
+|Function|Description|
+|---|---|
+|`float()`|converts to decimal number and returns it|
+|`int()`|converts to integer and returns it|
+|`input()`|function to take input from the user|
+
+---
+
+## Example
+
+#### Grading Student Based on Marks Obtained by Making Functions
+
+Suppose you just attended a University examination. The marks you obtained in various subjects are stored in a list like this:
+
+```python
+marks = [55, 64, 75, 80, 65]
+```
+
+**You want to find the average marks you obtained in the exam.**
+
+**Based on the average marks you want to find your grade as:**
+
+- **You will get Grade A if the average marks is equal to or above 80**
+- **You will get Grade B if the average marks is equal to or above 60 and less than 80**
+- **You will get Grade C if the average marks is equal to or above 50 and less than 60**
+- **And if the average marks is less than 50, you will get Grade F**
+
+```python
+# find the average marks and return it
+def find_average_marks(marks):
+    sum_of_marks = sum(marks)
+    number_of_subjects = len(marks)
+
+    average_marks = sum_of_marks/number_of_subjects
+
+    return average_marks
+
+# compute grade and return it
+def compute_grade(average_marks):
+    if average_marks >= 80.0:
+        grade = 'A'
+    elif average_marks >= 60:
+        grade = 'B'
+    elif average_marks >= 50:
+        grade = 'C'
+    else:
+        grade = 'F'
+
+    return grade
+
+marks = [55, 64, 75, 80, 65]
+average_marks = find_average_marks(marks)
+grade =compute_grade(average_marks)
+
+print("Your average marks is", average_marks)
+print("Your grade is", grade)
+```
+
+**Output**
+```
+Your average marks is 67.8
+Your grade is B
+```
+
+---
+
+## Programming Task
+
+**Can you create a program to add and multiply two numbers?**
+
+**For this, create two functions `add_numbers()` and `multiply_numbers()`.
+These functions should compute the result and return them to the function call and should print from outside the function.**
+
+
+```python
+# function to add two numbers
+def add_numbers(num1, num2):
+    return num1 + num2
+
+# function to multiply two numbers
+def multiply_numbers(num1, num2):
+    return num1 * num2
+
+number1 = 5
+number2 = 30
+
+num_sum = add_numbers(number1, number2)
+print("Sum is", num_sum)
+
+num_product = multiply_numbers(number1, number2)
+print("Product is", num_product)
+```
+
+**Output**
+
+```
+Sum is 35
+Product is 150
+```