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Semester 1: Python Programming
Introduction: Python Introduction, Numbers, Strings, Variables, Lists, Tuples, Dictionaries, Sets, Comparison
Python Programming
M.Sc Computer Science
Core III
1
Periyar University
23PCSC03
Python Introduction
Introduction to Python
Python is a high-level, interpreted programming language known for its readability and simplicity. It supports multiple programming paradigms, including procedural, object-oriented, and functional programming.
Numbers
Python supports various numerical data types, such as integers, floats, and complex numbers. It provides a built-in library for mathematical operations.
Strings
Strings in Python are sequences of characters enclosed in single or double quotes. They support various operations like slicing, concatenation, and formatting.
Variables
Variables in Python are used to store information. They do not require explicit declaration and can hold various data types, including numbers, strings, and collections.
Lists
Lists are ordered collections of items in Python. They can contain elements of different data types and support operations like indexing, slicing, and appending.
Tuples
Tuples are similar to lists but are immutable. Once created, their contents cannot be changed. They are useful for storing fixed collections of items.
Dictionaries
Dictionaries are unordered collections of key-value pairs. They are mutable and allow for fast retrieval of values based on their corresponding keys.
Sets
Sets are unordered collections of unique elements. They support mathematical set operations like union, intersection, and difference.
Comparison of Data Structures
Different data structures in Python serve varying purposes. Lists allow for ordered items, while sets ensure uniqueness. Dictionaries facilitate fast lookups through key-value mapping, and tuples provide immutable sequences.
Code Structures: if, elseif, else, while loop, for loop, Comprehensions, Functions, Generators, Decorators, Namespaces and Scope, Error handling with try except, User Exceptions
Code Structures
if, elseif, else
These are control flow statements used to make decisions in code. An if statement evaluates a condition and executes a block of code if true. An elseif can be used to check another condition if the first is false. An else statement provides an alternative block of code if all previous conditions are false.
while loop
A while loop repeatedly executes a block of code as long as a specified condition is true. It is important to ensure that the condition will eventually become false to avoid infinite loops.
for loop
A for loop iterates over a sequence (like a list or range). It allows executing a block of code for each item in the sequence, making it useful for collections.
Comprehensions
Comprehensions provide a concise way to create lists, sets, or dictionaries. They follow the format of an expression followed by a for clause, and can be optionally followed by an if clause.
Functions
Functions are reusable blocks of code that perform a specific task. They can take parameters and return values. Defining functions promotes code reusability and organization.
Generators
Generators are a type of iterable, similar to lists but do not store their contents in memory at once. They yield values one at a time, making them memory efficient.
Decorators
Decorators are functions that modify the functionality of another function. They allow adding behavior to existing functions in a clean and readable way.
Namespaces and Scope
Namespaces are containers for variable names, and scope refers to the visibility of these names. Understanding scope helps prevent naming conflicts and errors in code.
Error handling with try except
This structure allows programmers to handle exceptions gracefully. Code that may throw an error is placed in a try block, while the except block defines how to respond to that error.
User Exceptions
Custom exceptions can be created to handle specific error cases in programs. This allows for clearer error handling and more informative error messages.
Modules, Packages and Classes: Standalone Programs, Command-Line Arguments, Modules and import Statement, Python Standard Library, Define a Class, Inheritance, Method Overriding, Method Types, Duck Typing, Special Methods
Modules, Packages and Classes in Python
Standalone Programs
A standalone program is a complete Python application that can run independently. It typically includes a main block that defines the entry point of the program. Standalone scripts are often used for small tasks or prototypes.
Command-Line Arguments
Command-line arguments allow users to pass parameters to a Python program when it is executed. The sys module provides access to these arguments through sys.argv, which is a list of command-line arguments. This feature enhances the flexibility of scripts.
Modules and Import Statement
A module is a file containing Python code that can define functions, classes, and variables. Modules help organize code and promote reusability. The import statement is used to include modules into a script, allowing access to their content.
Python Standard Library
The Python standard library is a collection of modules and packages included with Python installations. It provides a wide variety of tools and functionalities, covering areas such as OS interaction, file manipulation, and data management, which can be leveraged without external installations.
Define a Class
Classes are blueprints for creating objects in Python. They encapsulate data and functions related to that data. The class definition includes attributes (variables) and methods (functions), allowing for data manipulation and behavior.
Inheritance
Inheritance allows a new class (child class) to inherit attributes and methods from an existing class (parent class). This promotes code reuse and establishes a hierarchy between classes. Python supports single and multiple inheritance.
Method Overriding
Method overriding occurs when a child class defines a method that already exists in its parent class. The child class method replaces the parent class method of the same name. This allows for customization and extension of functionality.
Method Types
Methods in Python can be categorized as instance methods (operate on instance data), class methods (operate on class data using the @classmethod decorator), and static methods (have no access to class or instance data, defined with @staticmethod).
Duck Typing
Duck typing is a concept in Python that emphasizes that the suitability of an object is determined by its methods and properties rather than its actual type. If an object behaves like a certain type, it can be treated as that type.
Special Methods
Special methods, also known as magic methods, are predefined methods in Python that start and end with double underscores (e.g., __init__, __str__). They allow customization of built-in behaviors of objects such as initialization, string representation, and arithmetic operations.
Data Types and Web: Text Strings, Binary Data, File Input/Output, Structured Text Files, Structured Binary Files, Relational Databases, NoSQL Data Stores, Web Clients, Web Servers, Web Services and Automation
Data Types and Web
Text Strings
Text strings are sequences of characters used to represent textual data in programming and databases. They can include letters, numbers, symbols, and spaces. In web contexts, text strings are often used in URLs, HTML elements, and JavaScript. They are usually enclosed in quotes and can be manipulated through various string functions.
Binary Data
Binary data refers to data that is in a format that is not directly readable by humans. This includes images, audio files, and executable files. Binary data is essential for encoding rich media content on the web. It typically requires specific handling to read and write correctly, such as using buffers and types specific to the binary format.
File Input/Output
File input/output (I/O) involves reading from and writing to files on a storage medium. In web development, input/output can occur with plain text files, binary files, and are facilitated through various programming languages and libraries, typically handling data streams that allow for synchronous or asynchronous processing.
Structured Text Files
Structured text files format data using a predefined structure, such as CSV or XML. This structure aids in parsing and data exchange between systems. They are widely used for data import/export operations in software applications and for web services that require data to be exchanged in a standardized format.
Structured Binary Files
Structured binary files store data in a binary format while maintaining an internal structure, which helps software to interpret the data correctly. Examples include certain image formats and proprietary data files used by applications. They offer efficiency in storage and retrieval processes.
Relational Databases
Relational databases are structured to recognize relations among stored items. They use tables to store data, with relationships established via primary and foreign keys. SQL (Structured Query Language) is commonly employed for managing and querying data in these databases, making them suitable for applications that require complex queries and transaction support.
NoSQL Data Stores
NoSQL data stores provide flexible schema designs to handle unstructured data. Types include key-value stores, document stores, and graph databases. They are advantageous in big data and real-time web applications where scalability, flexible data models, and high-performance data retrieval are crucial.
Web Clients
Web clients, or browsers, request resources from web servers and render content for users. They interact with the web server using protocols like HTTP/HTTPS. Clients can execute scripts, handle cookies, and maintain user sessions to provide a dynamic browsing experience.
Web Servers
Web servers host websites and serve web pages to clients. They process requests received from clients, often using HTTP, and send back responses (HTML, images, etc.). Server configuration includes handling multiple clients simultaneously and ensuring data is delivered securely.
Web Services and Automation
Web services allow applications to communicate over the internet using standardized protocols like SOAP and REST. Automation can be achieved using scripts and tools to interact with web services for tasks such as data retrieval, updates, or batch processing, facilitating integration between different software systems.
Systems and Networks: Files, Directories, Programs and Processes, Calendars and Clocks, Concurrency (Queues, Processes, Threads), Networking (TCP/IP, Sockets, ZeroMQ, Internet Services, APIs), Big Data and MapReduce, Cloud Computing
Systems and Networks
Files and Directories
Files are collections of data stored on a system. They have attributes like name, type, and size. Directories are organizational units that hold files and other directories, enabling hierarchical storage. File systems manage how data is stored and retrieved.
Programs and Processes
A program is a set of instructions for the computer. When executed, it becomes a process, which is an instance of a program in execution with its own memory space and process ID. Processes can be either foreground or background, affecting user interaction.
Calendars and Clocks
System clocks keep track of time in computing devices. Calendars are used to manage and organize events. Synchronization of clocks is crucial for distributed systems to ensure consistency and coordination across networked devices.
Concurrency
Concurrency involves multiple processes or threads executing simultaneously. Queues manage the execution order of processes, while threads are lightweight processes that share the same memory space, allowing for efficient multitasking.
Networking
Networking connects computers to share resources and information. TCP/IP is the foundational protocol suite, with sockets providing endpoints for communication. ZeroMQ offers a messaging library for distributed applications. Internet services and APIs facilitate access to remote resources.
Big Data and MapReduce
Big Data refers to the vast volume of data generated every second. MapReduce is a programming model for processing large datasets efficiently by dividing tasks (map) and aggregating results (reduce) across distributed systems.
Cloud Computing
Cloud computing delivers computing services over the internet. It offers scalability, flexibility, and cost-efficiency, with models like Infrastructure as a Service (IaaS) and Software as a Service (SaaS) enabling businesses to leverage resources without heavy investment in hardware.
Contemporary Issues: Expert lectures, online seminars, webinars
Contemporary Issues: Expert lectures, online seminars, webinars
Definition and Importance
Contemporary issues refer to current topics and challenges that are relevant in society. Expert lectures provide insights from professionals on these issues, making them crucial for understanding current trends.
Role of Online Seminars
Online seminars serve as platforms for experts to share knowledge and engage with audiences remotely. They are essential in disseminating information quickly and efficiently.
Webinars as Learning Tools
Webinars offer interactive experiences where participants can discuss contemporary issues in real-time. These sessions foster collaboration and networking among attendees.
Impact on Education and Professional Development
Expert lectures and webinars enhance educational experiences by providing real-world perspectives. They are valuable for professionals seeking to stay updated in their fields.
Accessibility and Inclusivity
Online formats increase accessibility to expert knowledge, allowing individuals from diverse backgrounds to participate regardless of geographical barriers.
Future Trends in Online Learning
The shift towards digital platforms for learning will continue to grow. Innovations in technology will further enhance the effectiveness of online seminars and webinars.
