Python (CS-506) - Important Questions

Explain how to connect to an SQLite database in Python. Write a complete program to create a table named "students" with columns (id INTEGER PRIMARY KEY, name TEXT, marks REAL), insert at least three records using parameterized queries, fetch and display all records, and demonstrate transaction commit and rollback.

Describe and implement a multi-threaded TCP server in Python that can serve multiple clients concurrently. Provide the server code showing socket setup, thread creation for each client connection, client-handling function, and graceful shutdown. Explain the role of the Global Interpreter Lock (GIL) and how it affects I/O-bound vs CPU-bound tasks in this server.

Discuss synchronization mechanisms in Python threading. Provide example code using threading.Lock and threading.RLock to protect a shared counter updated by multiple threads. Explain the concept of deadlock, show a small code example that may cause deadlock, and list strategies to avoid deadlock.

Write a Python Flask RESTful API with two endpoints: GET /students to return a JSON list of students and POST /students to add a new student. Show request parsing, basic input validation, error handling, and instructions to run the application.

Explain socket programming for UDP in Python. Write a UDP client-server pair where the client sends a text message and the server receives it, computes the length of the message, and sends the length back to the client. Include code for both client and server.

Design a GUI application using Tkinter that accepts user name and age, displays the entries in a Listbox, and provides Add and Delete buttons. Include event handling, input validation, and use of geometry managers (grid or pack) in your implementation.

Explain how to handle database errors and prevent SQL injection in Python database operations. Provide example code that uses parameterized queries, demonstrates exception handling for database errors, and describes input validation techniques.

Compare multithreading and multiprocessing in Python. Explain when to choose threading versus multiprocessing. Provide example code showing creation of a child process using multiprocessing.Process and describe basic inter-process communication (IPC) methods.

Describe how to write unit tests in Python using the unittest module. Write test cases for a function that computes factorial, demonstrating the use of setUp and tearDown methods and asserting expected outcomes, including handling invalid inputs.

Explain Python context managers and the semantics of the with statement. Implement a custom context manager class using the enter and exit methods that measures and prints the execution time of a code block.

Describe how to perform binary file I/O in Python and demonstrate object serialization using the pickle module. Provide code to serialize a dictionary of student records to a file and then deserialize it back into a Python object.

Discuss logging in Python. Show how to configure the logging module to write messages to a file with a specified format and logging level. Provide sample code that logs INFO and ERROR messages and explain how to use RotatingFileHandler to rotate log files.