1. Introduction to PYTHON
Rashid Ahmad Department of Physics, KUST

2. Anaconda Open Source Distribution
Over 15 million users worldwide
Develop and train machine learning and deep learning models with Scikit-learn, TensorFlow, and Theano
2. Integrated Development Environments
Spyder
Jupytor

3. Hello World The print() function Exercises Print the following Example
I’ m “your name”
Use single(double) quotation marks inside each other
Use print() as calculator
Use Escape Sequence
The print() function
Example
print(“Hello World”)
print(‘Hello World’)
print(‘Hello \’ nice \’ World’)

4. Variables, Numbers and Strings
Exercises
Input the username and print it in the reverse order
Hint: Use input function
e.g. Name = Input()
2. Print only first and third letters of the name
Casting
int(), float(), str()
Example
int(2.5)
str(4)
float(‘4’)
String Indexing
name = ‘Python’
print(name[0:1:5])

5. String Methods s = ‘ hello, world! ’, q = ‘I am {}’, age = 25
1. strip() print(s.strip()) returns ‘hello, world!’
2. len() print(len(s)) returns
3. lower() print(s.lower()) returns ‘hello, world!’
upper() print(s.upper()) returns ‘HELLO, WORLD!’
title() print(s.title()) returns ‘Hello, World!’
replace() print(s.replace(“,”, “ ”)) returns ‘Hello World!’
split() print(s.split(","))  returns ['Hello', ' World!']
format() print(q.format(age)) returns I am 36
find() print(s.find(‘w’)) returns
center() print(s.center(10)) returns hello, world!

6. String Methods Exercises
Take two coma separated inputs from user (name and one character of the name) and count the occurrence of that character of the name
Use the format and method to create a string

7. Arithmetic and Assignment Operators
Arithmetic operators: they are used with numeric values to perform common mathematical operations:
Assignment operators: they are used to assign values to variables:
Operator
Name
Example +
Addition
x + y -
Subtraction
x - y *
Multiplication
x * y /
Division
x / y %
Modulus
x % y **
Exponentiation
x ** y //
Float division
x // y
Operator
Example
Same As =
x = 5 +=
x += 3
x = x + 3 -=
x -= 3
x = x - 3 *=
x *= 3
x = x * 3 /=
x /= 3
x = x / 3 %=
x %= 3
x = x % 3
//=
x //= 3
x = x // 3
**=
x **= 3
x = x ** 3
&=
x &= 3
x = x & 3 |=
x |= 3
x = x | 3 ^=
x ^= 3
x = x ^ 3
>>=
x >>= 3
x = x >> 3
<<=
x <<= 3
x = x << 3

8. Comparison and Logical Operators
Comparison operators: they are used to compare two values:
Logical operators: they are used to combine conditional statements:
Operator
Name
Example ==
Equal
x == y !=
Not equal
x != y
>
Greater than
x > y
<
Less than
x < y
>=
Greater than or equal to
x >= y
<=
Less than or equal to
x <= y
Operator
Description
Example
and 
Returns True if both statements are true
x < 5 and  x < 10 or
Returns True if one of the statements is true
x < 5 or x < 4
not
Reverse the result, returns False if the result is true
not(x < 5 and x < 10)

9. Identity and Membership Operators
Identity operators: they are used to compare the objects, not if they are equal, but if they are actually the same object, with the same memory location:
Membership operators: they are used to test if a sequence is presented in an object:
Operator
Description
Example
in 
Returns True if a sequence with the specified value is present in the object
x in y
not in
Returns True if a sequence with the specified value is not present in the object
x not in y
Operator
Description
Example
is 
Returns true if both variables are the same object
x is y
is not
Returns true if both variables are not the same object
x is not y

10. Loop Statements 3. If else Statement Example
a = 10 b = 20 if b > a:    print(“b is greater than a”)
elif a == b:    print("a and b are equal")
else:
print(“a is greater than b”)
1. If Statement Example a = 10 b = 20 if b > a: print(“b is greater than a”) 2. If else Statement a = 33 b = 200 if b > a: print(“b is greater than a”) else: print(“a is greater than b”)

11. If else elif statement Exercises
Create a game in which user guesses some random number
Write a program which checks eligibility of a student for admission based on Test Score and CGPA

12. The While Loop
It executes set of statements as long as given condition is true
The While Statement
Example
i = 1 while i < 6:   print(i)   i += 1
3. The continue Statement
Example
i = 0
while i < 6:
i += 1
if i == 3:
continue
print(i)
The Break Statement
Example
i = 1
while i < 6:
print(i)
if i == 3:
break
i += 1

13. The For Loop
Execute a set of statements, once for each item 1. The Simple for Loop Example fruits = ["apple", "banana", "cherry"] for x in fruits: print(x)
The for else loop
Example
for x in range(6):   print(x) else:   print("Finally finished!")
4. Nested Loops
Example
adj = ["red", "big", "tasty"] fruits = ["apple", "banana", "cherry"] for x in adj: for y in fruits:     print(x, y)
The Range Function
Example
for i in range(2, 30, 3):   print(f“Welcome {i}’’)

14. List and Its Methods
Changeable ordered collection of objects 1. Creating List Example fruits = ["apple", "banana", "cherry"] print(fruits)
Method
Description
append()
Adds an element at the end of the list
clear()
Removes all the elements from the list
copy()
Returns a copy of the list
count()
Returns the number of elements with the specified value
extend()
Add the elements of a list (or any iterable), to the end of the current list
index()
Returns the index of the first element with the specified value
insert()
Adds an element at the specified position
pop()
Removes the element at the specified position
remove()
Removes the item with the specified value
reverse()
Reverses the order of the list
sort()
Sorts the list
2. The insert method
Example
fruits = ["apple", "banana", "cherry"]
fruits.insert(1, "orange")
  print(fruits)

15. Tuple and Its Methods
Unchangeable ordered collection of objects 1. Creating Tuple Example fruits = ("apple", "banana", "cherry”) print(fruits)
3. Adding Items is not Possible
Example
fruits = ("apple", "banana", "cherry”)
Fruits[3] = “orange” # error will be raised
 print(fruits)
2. Check if Item Exists
Example
fruits = ("apple", "banana", "cherry”)
if "apple" in fruits:   print("Yes, 'apple' is in the fruits tuple")
Method
Description
count()
Returns the number of times a specified value occurs in a tuple
index()
Searches the tuple for a specified value and returns the position of where it was found

16. Sets and Its Methods
Method
Description
add()
Adds an element to the set
clear()
Removes all the elements from the set
copy()
Returns a copy of the set
difference()
Returns a set containing the difference between two or more sets
difference_update()
Removes the items in this set that are also included in another, specified set
discard()
Remove the specified item
intersection()
Returns a set, that is the intersection of two other sets
intersection_update()
Removes the items in this set that are not present in other, specified set(s)
isdisjoint()
Returns whether two sets have a intersection or not
issubset()
Returns whether another set contains this set or not
issuperset()
Returns whether this set contains another set or not
pop()
Removes an element from the set
remove()
Removes the specified element
symmetric_difference()
Returns a set with the symmetric differences of two sets
symmetric_difference_update()
inserts the symmetric differences from this set and another
union()
Return a set containing the union of sets
update()
Update the set with the union of this set and others
A set is a collection which is unordered and unindexed 1. Creating Set Example fruits = {"apple", "banana", "cherry”} print(fruits)
The del keyword
Example
fruits = ("apple", "banana", "cherry”)
del fruits
print(fruits)

17. Dictionaries and Its Methods
A dictionary is a collection which is ordered, changeable and indexed
Creating Dictionary
Example
student = {“name“: “Rashid”, “GPA", 3.4}  print(student)
Method
Description
clear()
Removes all the elements from the dictionary
copy()
Returns a copy of the dictionary
fromkeys()
Returns a dictionary with the specified keys and values
get()
Returns the value of the specified key
items()
Returns a list containing the a tuple for each key value pair
keys()
Returns a list containing the dictionary's keys
pop()
Removes the element with the specified key
popitem()
Removes the last inserted key-value pair
setdefault()
Returns the value of the specified key. If the key does not exist: insert the key, with the specified value
update()
Updates the dictionary with the specified key-value pairs
values()
Returns a list of all the values in the dictionary
Accessing Items
Example
student = {“name“: “Rashid”, “GPA", 3.4}  print(student.get(“name”))

18. Arrays and Its Methods
An array is a special variable, which can hold more than one value at a time.
Creating Array
Example
student = [“A”, “B”, “C”, “D”, “E”]  print(student)
Method
Description
append()
Adds an element at the end of the list
clear()
Removes all the elements from the list
copy()
Returns a copy of the list
count()
Returns the number of elements with the specified value
extend()
Add the elements of a list (or any iterable), to the end of the current list
index()
Returns the index of the first element with the specified value
insert()
Adds an element at the specified position
pop()
Removes the element at the specified position
remove()
Removes the first item with the specified value
reverse()
Reverses the order of the list
sort()
Sorts the list
Accessing Items
Example
student = {“name“: “Rashid”, “GPA", 3.4}  print(student.get(“name”))

19. Functions
A function is a set of statements that take inputs, do some specific computation and produces output.
Defining Function
Example
def add_two(a,b):
return a+b
print(add_two(4,5))
Exercises
Define a function which takes name as input from user and print its last character
Define a function which takes two numbers as input and returns the greater number
Define a function which generates the Fibonacci Series
2. Concatenate Strings
Example
First_name = input(‘’Enter your first name:”)
Second_name = input(‘’Enter your Second name:”)
print(add_two(First_name , Second_name))

20. Classes and Objects The built-in __init__() function class LHC_school:
Class:  It is a structure created for defining an object. It contains a set of attributes that characterizes any object that is instantiated from this class.
Creating a Class
class  MyClass:   x = 5
Object:  It is an instance of a class. This is the realized version of the class, where the class is manifested in the program.
Creating an object
obj =  MyClass()
print(obj.x)
The built-in __init__() function
class LHC_school:
def __init__(self)
print(“This is 8th LHC School”)
P1= LHC_school()
print(P1)

21. LHC Class class LHC_school:
def __init__(self, name, number, place, month, period, year):
self.name = name
self.number = number
self.place = place
self.month = month
self.period = period
self.year = year
def venue(self):
print(self.name + self.place)
def which(self):
print(self.number)
def summer(self):
print(self.month)
def date(self):
print(self.period)
def season(self):
print(self.year)
def main():
This_year = LHC_school("LHC School ", "8th", "held in Islamabad", "August", "19-30", "2019")
This_year.venue()
This_year.which()
This_year.summer()
This_year.date()
This_year.season()
if __name__ == "__main__":
main()

22. I Thank You All!