Class 12 Computer Science - Python Revision Tour PDF

Page 1 NITIN PALIWAL  Page 2 CLASS 12 COMPUTER SCIENCE PYTHON REVISION TOUR INTRODUCTION TO PYTHON Python is a high level, general purpose programming language. ADVANTAGES OF PYTHON: Readability: Clear and easy-to-under...

Page 1 NITIN PALIWAL  Page 2 CLASS 12 COMPUTER SCIENCE PYTHON REVISION TOUR INTRODUCTION TO PYTHON Python is a high level, general purpose programming language. ADVANTAGES OF PYTHON: Readability: Clear and easy-to-understand syntax. Large Standard Library: Extensive pre-built modules for various tasks. Versatility: Suitable for web development, data science, and more. Community Support: Active community providing resources and libraries. Integration Capabilities: Easily integrates with other languages. Rapid Development: Quick prototyping and development. Cross-Platform: Compatible with major operating systems. Scalability: Can be used in large-scale applications. DISADVANTAGES OF PYTHON: Speed: Interpreted nature may be slower than compiled languages. Global Interpreter Lock (GIL): Limits thread execution on multi-core systems. Mobile Development: Not the primary choice for mobile app development. Design Restrictions: Some developers may find design philosophies limiting. Memory Consumption: May use more memory, especially in resource-constrained environments. Threading Limitations: Challenges in leveraging multi-core processors. Packaging Issues: Managing dependencies can be challenging. Less Suitable for Resource-Intensive Tasks: Performance may not match languages designed for resource-intensive tasks. PYTHON: ADVANTAGES AND DISADVANTAGES Advantages Disadvantages 1. Readability 1. Speed 2. Large Standard Library 2. Global Interpreter Lock (GIL) NITIN PALIWAL  Page 3 Advantages Disadvantages 3. Versatility 3. Mobile Development 4. Community Support 4. Design Restrictions 5. Integration Capabilities 5. Memory Consumption 6. Rapid Development 6. Threading Limitations 7. Cross-Platform 7. Packaging Issues 8. Less Suitable for Resource-Intensive 8. Scalability Tasks TOKENS TOKENS KEYWORD IDENTIFIER LITERALS PUNCTUATION OPERATOR Reserved Symbols Symbols Words with Names given Constants or used to that predefined to various fixed values structure perform meaning in program used in a code and operations the elements. program. separate on variables language. statements. and values. Tokens: The smallest individual unit in a program is known as Token LITERALS IDENTIFIERS KEYWORDS OPERATORS IDENTIFIERS NITIN PALIWAL  Page 4 KEYWORDS: RESEVED WORDS Keyword Description and Logical operator for conjunction (logical AND). as Used to create an alias for a module or symbol. assert Used for debugging to check if a condition is true. break Terminates the loop prematurely. class Declares a class in object-oriented programming. continue Skips the rest of the loop's code and continues to the next iteration. def Defines a function. del Deletes an object or a part of an object. elif Stands for "else if" and is used in conditional statements. else Specifies a block of code to be executed if the condition is false. except Catches exceptions during exception handling. False Boolean value representing false. finally Specifies a block of code to be executed, regardless of the try-except block. for Used to iterate over a sequence (e.g., list, tuple, string). from Used to import specific attributes or functions from a module. global Declares a global variable. if Conditional statement, executes code if a specified condition is true. import Imports a module into the current program. in Membership test, checks if a value exists in a sequence. is Compares object identity. lambda Creates an anonymous function (lambda function). None Represents the absence of a value or a null value. not Logical operator for negation (logical NOT). or Logical operator for disjunction (logical OR). pass Placeholder indicating no action to be taken. raise Raises an exception. return Exits a function and returns a value. True Boolean value representing true. try Defines a block of code to be tested for errors. Creates a loop that executes a block of code as long as a specified while condition is true. Simplifies resource management (e.g., file handling) using a context with manager. Pauses the execution of a generator function and returns a value to the yield caller. NITIN PALIWAL  Page 5 IDENTIFIERS Rules for Identifiers:  Must start with a letter (a-z, A-Z) or an underscore (_).  The remaining characters can be letters, underscores, or digits (0-9).  Case-sensitive (myVar and myvar are different). Examples of Identifiers: Valid:  my_variable  count_1  PI  _underscore  Name123 Invalid:  123abc (starts with a digit)  my-var (contains a hyphen)  if (using a Python keyword)  spaces not allowed  #hash_symbol (contains a special character) LITERALS Single Quotes: 'Hello' STRING Double Quotes: "World" Triple Quotes: '''Multi-line string''' BOOLEAN TRUE AND FALSE NONE Represents the absence of a value LITERALS Integers: 42, -10 NUMERIC Floats: 3.14, -0.5 Complex Numbers: 2 + 3j Lists: [1, 2, 3] LITERAL Tuples: (1, 2, 3) COLLECTIONS Sets: {1, 2, 3} Dictionaries: {'key': 'value'} NITIN PALIWAL  Page 6 PUNCTUATIONS  Definition: Punctuations are symbols used to structure code and separate statements in Python.  Common Punctuations:  Semicolon (;):  Separates multiple statements on the same line.  Comma (,):  Separates items in a tuple or elements in a list.  Period (.):  Accesses attributes or methods of an object. OPERATORS Perform mathematical operations like addition, ARITHMETIC subtraction, multiplication, and division. Example: +, -, *, / COMPARISON Compare values and return True or False. Example: == (equal), != (not equal), > (greater than) OPERATORS LOGICAL Combine conditions and return True or False. Example: and, or, not ASSIGNMENT Assign values to variables. Example: =,+=,-= IDENTITY Check if two objects are the same. Example: is/ is not MEMBERSHIP Test if a value is a member of a sequence. Example: in, in not BITWISE Perform bit-level operations. Example: &, |, ^ NITIN PALIWAL  Page 7 EXECUTING PYTHON PROGRAMS Printing a simple “Hello Maharathi” Program INPUT: OUTPUT: DATA TYPES IN PYTHON DATA TYPES NUMBER 1) Integer DICTIONARY 2) Float 3) Complex Number 1) Unordered collection of key-value pairs. 2) Defined by curly braces ({}) with key-value pairs. 3) Example: person = {'name': 'John', 'age': 25} STRING 1) 2) Sequences of characters. Enclosed in single (' '), double SET (" "), or triple quotes. 1) Unordered, mutable collection with unique 3) Example: text = "Hello, World!" elements. 2) Defined by curly braces ({}). 3) Example: unique numbers = {1, 2, 3} BOOLEAN 1) Represents truth values: True or False. 2) Used for logical operations and conditions. TUPLE 3) Example: is_true = True 1) Ordered, immutable collection. 2) Defined by parentheses (()). 3) Example: coordinates = (x, y) LIST 1) Ordered, mutable collection. 2) Defined by square brackets ([]). 3) Example: numbers = [1, 2, 3] NITIN PALIWAL  Page 8 CONDITIONAL STATEMENTS If Statement:  Executes a block of code if a condition is true. INPUT: EXAMPLE : Checking if a number is positive with the help of if statement INPUT: OUTPUT: NITIN PALIWAL  Page 9 If-Else Statement:  Executes one block of code if a condition is true and another if it's false. INPUT: EXAMPLE : Checking if a number is positive or negative INPUT: OUTPUT: OUTPUT: NITIN PALIWAL  Page 10 If-Elif-Else Statement:  Checks multiple conditions in sequence.  Executes the block corresponding to the first true condition. INPUT: EXAMPLE : Checking the sign of a number INPUT: OUTPUT: NITIN PALIWAL  Page 11 SIMPLE PYTHON PROGRAMS Absolute Value Program:  Calculates the absolute value of a number.  The absolute value of a number is never negative.  Coverts negative number to positive and positive number remains the same EXAMPLE : Finding absolute value of -5 INPUT: OUTPUT: Sort 3 Numbers Program:  Sorts three numbers in ascending order. EXAMPLE : Sorting 3 numbers in ascending order INPUT: OUTPUT: NITIN PALIWAL  Page 12 Divisibility Check Program:  Checks if a number is divisible by another number. EXAMPLE : Checking if 10 is divisible by 2 INPUT: OUTPUT: NITIN PALIWAL  Page 13 FOR AND WHILE LOOP For Loop Program:  Iterates over a sequence (list, tuple, string, etc.) or a range of values. EXAMPLE : Calculate the square of numbers using for loop INPUT: OUTPUT: NITIN PALIWAL  Page 14 While Loop Programs:  Repeats a block of code as long as a condition is true. EXAMPLE : Calculating the factorial of a number using loop INPUT: OUTPUT: NITIN PALIWAL