CLASS-11 & 12 ICT PPT PYTHON PROGRAMMING.pptx

Fundamentals of Python Programming
•Interactive, interpreted, and object-oriented
programming language.
• Platform independent.
•Simple syntax, Free and Open source.
• Portable, extensible and expandable.
• Large standard libraries to solve a task.
•Developed by Guido Van Rossum in 1991 at the
National Research Institute for Mathematics and
Computer Science in the Netherlands.
•Name was inspired by: Monty Python’s Flying
Circus.
• Allows to distinguish input, output, and error
messages by different colour codes.

PYTHON PROGRAMMING ENVIRONMENT
• Available on a wide variety of platforms including Windows,
Linux and Mac OS X.
• Official Website: python.org
• IDLE stands for Integrated Development and Learning
Environment. Python IDLE comprises of Python Shell and
Python Editor.
Python Shell Python Editor

• Reserved words that are already defined by the
Python for specific uses.
In [ ]: import keyword
print(keyword.kwlist)

Sample Python Command Line Expressions
Display on screen
In [2]: print('hello world')
hello world
Since, Python is a case-sensitive language so print and
PRINT are different.

Names (Variables) and Assignment Statements
• Variables provide a means to name values so that they can be
used and manipulated later.
• Assignment Statement: Statement that assigns value to a
variable.
In [ ]: Maths = 87
print(Maths)
87
Python associates the name (variable) Maths with value 87 i.e.
the name (variable) Maths is assigned the value 87, or that the
name (variable) Maths refers to value 87. Values are also called
objects.

Multiple Assignments
•Used to enhance the readability of the program.
>>> msg, day, time='Meeting','Mon','9‘
>>> print (msg,day,time)
Meeting Mon 9
totalMarks = count = 0
Data Types and Associating them with variables

Arithmetic Operators
print("18 + 5 =", 18 + 5)
print("18 - 5 =", 18 - 5)
print("18 * 5 =", 18 * 5)
print("27 / 5 =", 27 / 5)
print("27 // 5 =", 27 // 5)
print("27 5 =", 27 5)
print("2 ** 3 =", 2 ** 3)
print("-2 ** 3 =", -2 ** 3)
18 + 5 = 23
18 - 5 = 13
18 * 5 = 90
27 / 5 = 5.4
27 // 5 = 5
27 5 = 2
2 ** 3 = 8
-2 ** 3 = -8
#Addition
#Subtraction
#Multiplication
#Division
#Integer Division
#Modulus
#Exponentiation
#Exponentiation
Precedence of Arithmetic Operators
Operators in Python

Relational Operators
• Used for comparing two expressions and yield True or False.
• The arithmetic operators have higher precedence than the
relational operators.
print("23 < 25 :", 23 < 25)
print("23 > 25 :", 23 > 25)
print("23 <= 23 :", 23 <= 23) #less than or equal to
print("23 - 2.5 >= 5 * 4 :", 23 - 2.5 >= 5 * 4) #greater than or equal to
print("23 == 25 :", 23 == 25)
print("23 != 25 :", 23 != 25)
• When the relational operators are applied to strings, strings are compared
left to right, character by character, based on their ASCII codes, also called
ASCII values.
print("'hello' < 'Hello' :", 'hello' < 'Hello')
print("'hi' > 'hello' :", 'hi' > 'hello')
'hello' < 'Hello' : False
'hi' > 'hello' : True
#less than
#greater than
#equal to
#not equal to

Logical Operators
• The logical operators not, and, and or are applied to logical
operands True and False, also called Boolean values, and yield
either True or False.
• As compared to relational and arithmetic operators, logical
operators have the least precedence level.
print("not True < 25
print("10 < 25 and 5 >6
print("10 < 25 or 5 > 6
:", not True) #not operator
:", 10 < 25 and 5 > 6) #and operator
:", 10 < 25 or 5 > 6) #or operator
Identity Operators

Functions
• Functions provide a systematic way of problem solving by dividing the
given problem into several sub-problems, finding their individual
solutions, and integrating the solutions of individual problems to solve
the original problem.
• This approach to problem solving is called stepwise refinement method
or modular approach.
Built-in Functions
• Predefined functions that are already available in Python.
Type Conversion: int, float, str functions
>>>str(123)
'123'
>>>int('234')
234
>>>int(234.8)
234

input function
• Enables us to accept an input string from the user
without evaluating its value.
• The function input continues to read input text from the user until it
encounters a newline.
>>>name = input('Enter your name: ')
print('Welcome', name)
Enter your name: Yogesh
Welcome Yogesh
costPrice = int(input('Enter cost price: '))
profit = int(input('Enter profit: '))
sellingPrice = costPrice + profit
print('Selling Price: ' , sellingPrice)
Enter cost price: 50
Enter profit: 12
Selling Price: 62
Another
Example: To find
the profit earned
on an item

Function Definition and Call
The syntax for a function definition is as follows:
def function_name ( comma_separated_list_of_parameters):
statements
Note: Statements below def begin with four spaces. This is called indentation. It is a
require-ment of Python that the code following a colon must be indented.
def triangle():
' ' '
Objective: To print a right angled triangle. Input
Parameter: None
Return Value: None
' ' '
' ' '
Approach: To use a print statement for each line of output
' ' '
print('*')
print('* *')
print('* * *')
print('* * * *')
User-Defined Functions
Invoking the function
>>>triangle()
*
* *
* * *
* * * *

Computing Area of the Rectangle
def areaRectangle(length, breadth):
' ' '
Objective: To compute the area of rectangle Input
Parameters: length, breadth numeric value Return
Value: area - numeric value
' ' '
area = length * breadth
return area
>>>areaRectangle(7,5)
35
>>>help(areaRectangle) #help on any function
Help on function areaRectangle in module main :
areaRectangle(length, breadth)
Objective: To compute the area of rectangle
Input Parameters: length, breadth numeric value
Return Value: area - numeric value

#This else is for break and not for if statement

Strings, Lists, and
Dictionary

Strings
• A string is a sequence of characters.
• A string may be specified by placing the member characters of
the sequence within quotes
(single, double or triple).
• Triple quotes are typically used for strings that span multiple
lines.
>>>message = 'Hello Gita'
Computing Length using len function
>>>print(len(message))
10
Indexing
• Individual characters within a string are accessed using a technique
known as indexing.
>>>index = len(message) - 1
>>>print(message[0], message[6], message[index], message[-1])
H G a a
>>>print(message[15])
IndexError Traceback (most recent call last)
<ipython-input-4-a801df50d8d1> in <module>()

Slicing
• In order to extract the substring comprising the character sequence
having indices from start to end-1, we specify the range in the form
start:end.
• Python also allows us to extract a subsequence of the form
start:end:inc.
>>>message = 'Hello Sita'
>>>print(message[0:5], message[-10:-5])
Hello Hello
>>>print(message[0:len(message):2])
>>>print(message[:])
HloSt
Hello Sita
Membership Operator in
• Python also allows us to check for membership of the individual
characters or substrings in
strings using in operator.
>>>'h' in 'hello'
True
>>>'ell' in 'hello'
True
>>>'h' in 'Hello'
False

Lists
• A list is an ordered sequence of values.
• Values stored in a list can be of any type such as string, integer, float,
or list.
• Note!! Elements of a list are enclosed in square brackets, separated by
commas.
• Unlike strings, lists are mutable, and therefore, one may modify
individual elements of a list.
>>>subjects=['Hindi', 'English', 'Maths', 'History']
>>>temporary = subjects

>>>temporary[0] = 'Sanskrit'
>>>print(temporary)
>>>print(subjects)
['Sanskrit', 'English', 'Maths', 'History']
['Sanskrit', 'English', 'Maths', 'History']
>>>subjectCodes = [['Sanskrit', 43], ['English', 85] , ['Maths', 65],
['History', 36]]
>>>subjectCodes[1]
['English', 85]
>>>print(subjectCodes[1][0],subjectCodes[1][1])
English 85
List Operations
>>>list1 = ['Red', 'Green']
list2 = [10, 20, 30]
Multiple Operator *
>>>list2 * 2
[10, 20, 30, 10, 20, 30]
Concatenation Operator +
>>> list1 = list1 + ['Blue']
>>>list1
['Red', 'Green', 'Blue']

Length Operator len
>>>len(list1)
3
Indexing & Slicing
>>>list2[-1]
30
>>>list2[0:2]
[10, 20]
>>>list2[0:3:2]
[10, 30]
Function min & max
>>>min(list2)
10
>>>max(list1)
'Red'
Membership Operator: in
>>>40 in list2
False
>>>students = ['Ram', 'Shyam', 'Gita', 'Sita']
for name in students:
print(name)
Ram
Shyam
Gita
Sita

CLASS-11 & 12 ICT PPT PYTHON PROGRAMMING.pptx

Recommended

More Related Content

Similar to CLASS-11 & 12 ICT PPT PYTHON PROGRAMMING.pptx (20)

Recently uploaded (20)

CLASS-11 & 12 ICT PPT PYTHON PROGRAMMING.pptx