Python Web Development and Database Fundamentals

Posted on Dec 9, 2025 in Business Management and Information Technology

Python Development Knowledge Check

Flask Templating and Logic Separation

Q1: Flask Template Purpose

To separate presentation logic from application logic.

  • Flask template: HTML with placeholders.
  • Jinja2: Templating engine.
  • Presentation logic: User Interface (UI).
  • Application logic: Backend code.

Note: Separates UI from Python logic.

Python Object-Oriented Programming (OOP)

Q2: Purpose of super()

To call a parent class constructor.

  • super(): Access parent methods.
  • Inheritance: Child extends parent.
  • Constructor: __init__.

Note: Use super() in the child __init__.

Q3: Purpose of the @property Decorator

Allows a method to be called like a property.

  • Decorator: Modifies a function.
  • @property: Implements a getter.

Note: Enables attribute-style access.

Python Control Flow

Q4: Purpose of an if Statement

Execute code based on a condition.

  • Condition: Evaluates to True or False.

Note: Controls decisions in code.

Q5: Keyword for Alternative Condition

elif.

  • Chained conditions: Used for multiple branches.

Note: Use for multiple conditional branches.

Q6: Operator to Compare Values

== (Equality operator).

  • ==: Checks for equality.

Note: Do not confuse with = (assignment).

Q7: Function of an else Statement

Executes if no preceding conditions are met.

  • Default branch: The fallback execution path.

Note: Runs last.

Python Loops and Iteration

Q8: Example of a Loop

for loop.

  • Loop: Repeats a block of code.

Note: Iterates over collections.

Q9: Purpose of while Loop

Repeat execution while a condition remains true.

  • Condition loop: Repeats based on a boolean state.

Note: Danger of infinite loops if the condition never becomes false.

Q10: Keyword to Stop a Loop

break.

  • Break: Immediately exits the current loop.

Note: Used inside loops.

Q11: Output of for i in range(3)

0 1 2.

  • range(3): Generates numbers 0, 1, 2.

Note: Range starts at 0 by default.

Q12: Best Loop to Iterate a List

for loop.

  • Iteration: The process of repeating over items.

Note: The for loop is built for collections.

Python Data Structures

Q13: Access Value by Key ‘name’

dictionary['name'].

  • Dict: Stores key-value pairs.

Note: Keys must match exactly.

Q14: Output of len([1, 3])

2.

  • len(): Counts the number of items.

Note: The list has two items.

Q15: Method to Add a List Item

append().

  • Append: Adds an item to the end of the list.

Note: This is the most common addition method.

Q16: Type Storing Key-Values

Dictionary.

  • Mapping: Data structure based on key-value pairs.

Note: Keys must be unique.

Python Classes and OOP Foundation

Q17: Definition of a Class

A blueprint for creating objects.

  • Class template: Defines structure and behavior.

Note: The foundation of OOP.

Q18: Creating a Car Instance

car = Car().

  • Instance: An object created from a class.

Note: This calls the class constructor.

Q19: Purpose of __init__

To initialize a newly created object.

  • Constructor: Sets initial attributes for the object.

Note: Sets initial attributes.

Q20: Concept Inheritance Belongs To

OOP (Object-Oriented Programming).

  • Child reuses parent: Promotes code reuse.

Note: Focuses on code reuse.

SQL Database Commands

Q21: SQL Command to Delete Data

DELETE.

  • DELETE: Removes rows from a table.

Note: Often paired with a WHERE clause.

Q22: Select All From Students

SELECT * FROM students.

  • *: Represents all columns.
  • FROM table: Specifies the target table.

Q23: Command to Change Existing Data

UPDATE.

  • UPDATE: Modifies existing rows.

Note: Requires the SET clause.

Q24: Keyword to Filter Records

WHERE.

  • Condition filter: Specifies criteria for selection or modification.

Note: Used in SELECT, UPDATE, and DELETE.

Q25: SQL Command to Create a Table

CREATE TABLE.

  • DDL: Data Definition Language commands structure.

Note: Defines the database schema.

Q26: Command to Add a Column to a Table

ALTER TABLE.

  • ALTER: Modifies the structure of an existing table.

Note: Use with ADD COLUMN.

Q27: Not a Data Type

Loop.

  • Loop: A control structure, not a storage type.

Note: Data types store values.

SQLite Database Interaction

Q28: Library for SQLite

sqlite3.

  • Built-in: Included with standard Python installations.

Note: No external installation required.

Q29: Connect to an SQLite DB

sqlite3.connect('database.db').

  • Connection: Establishes a link to the database file.

Note: Creates the DB file if it does not exist.

Q30: Method to Execute SQL

execute().

  • Cursor executes: Sends commands to the database via a cursor object.

Note: Used to run SQL commands.

Q31: Object Used to Interact with DB

Cursor.

  • Cursor handles SQL: Manages command execution and result fetching.

Note: Used to fetch query results.

Q32: Save DB Changes

connection.commit().

  • Commit saves: Makes changes permanent in the database.

Note: Required for write operations (INSERT, UPDATE, DELETE).

Python Environments and Tools

Q33: What is a Virtual Environment?

A self-contained Python environment.

  • venv: Isolates project dependencies.

Note: Avoids dependency version conflicts between projects.

Q34: Purpose of a Virtual Environment

To manage project-specific dependencies.

  • Dependency: A required package or library.

Note: Dependencies are managed per-project.

Q35: IDE Stands For What?

Integrated Development Environment.

  • IDE: Combines an editor, debugger, and tools.

Note: Examples include VS Code and PyCharm.

Flask Web Framework Specifics

Q36: Flask is Used For

Web development.

  • Microframework: Provides core routing and templating capabilities.

Note: Focuses on routes and templates.

Q37: Method to Define a Route

@app.route().

  • Route: Maps a URL path to a Python function.

Note: This decorator binds the view function to a URL.

Q38: File Extension for Templates

.html.

  • HTML markup: Standard structure for web pages.

Note: Jinja syntax is embedded within these HTML files.

Q39: How to Start Flask Dev Server

flask run.

  • Dev server: Runs the application locally for testing.

Note: Requires the FLASK_APP environment variable to be set.

Python Operators and Testing

Q40: Test if an Element Exists

The in operator.

  • Membership operator: Checks for presence within a collection.

Note: Works on lists, sets, and dictionaries (keys).

Q41: What is Unit Testing?

Testing individual, isolated units of code.

  • Unit: The smallest testable piece of software.

Note: Common frameworks include pytest and unittest.

Q42: Purpose of Integration Testing

To test how multiple units work together.

  • Integration: Checks the interaction between combined components.

Note: Focuses on interface correctness.

Q43: Black-Box vs White-Box Testing

  • Black-box: Tests functionality without knowledge of internal code structure.
  • White-box: Tests based on internal logic and code visibility.

Notes: Black-box focuses on behavior; white-box focuses on structure.

Basic Data Types

Q44: Type of 3.14

Float (Floating-point number).

  • Float: A numeric type representing decimals.

Note: Used for non-integer numeric values.

Q45: What Boolean Holds

True or False.

  • Bool type: Represents logical truth values.

Note: Essential for conditional logic.

Git and Version Control

Q46: Command to Copy a GitHub Repo

git clone.

  • Clone: Downloads the entire repository history to a local machine.

Note: Creates a local working copy.

MVC Pattern and Flask Input

Q47: Purpose of venv

To isolate dependencies from the global Python installation.

  • Isolation: Keeps project requirements separate.

Note: Avoids version conflicts.

Q48: MVC Component for Business Logic

Model.

  • Model: Handles data representation and core business rules.

Note: Contains the core logic.

Q49: Module for CSV Files

csv.

  • CSV: Comma-Separated Values format.

Note: Provides reader and writer objects.

Q50: Purpose of Controller in MVC

To handle user input and coordinate the Model and View layers.

  • Controller: Acts as the logic glue or mediator between input and data/presentation.

Q51: Flask Object for Form Data

request.form.

  • Request: Holds incoming data from the client.

Note: Used primarily for data submitted via POST forms.

Q52: Method Used to Insert New Record

POST.

  • POST: Used to send data to the server for creation or submission.

Note: Standard method for form submissions creating new resources.

Q53: Why Server-Side Validation?

Because client-side validation can be easily bypassed by malicious users.

  • Validation: The process of checking data integrity.

Note: Backend must always verify input.

Containerization and DevOps

Q54: What is a Docker Container?

A lightweight, isolated environment packaging an application and all its dependencies.

  • Container: A packaged, runnable instance of an image.

Note: Ensures consistent behavior across different machines.

Q55: File Defining a Docker Image

Dockerfile.

  • Build file: Contains step-by-step instructions for building the image.

Q56: Detached Mode Command

docker run -d.

  • -d: Runs the container in the background (detached).

Note: Does not block the terminal session.

Q57: Advantage of Docker

It ensures consistent behavior across all deployment systems.

  • Consistent environment: Eliminates “it works on my machine” problems.

Q58: Shift-Left Testing Means

Testing activities begin earlier in the Software Development Life Cycle (SDLC).

  • Early testing: Finding and fixing defects sooner is cheaper.

Q59: CI/CD Stands For

Continuous Integration / Continuous Delivery (or Deployment).

  • CI: Frequent merging of code changes.
  • CD: Automation of software release processes.

Note: Focuses on pipeline automation.

Q60: Main Goal of DevSecOps

To integrate security practices throughout the entire DevOps pipeline.

  • Security early: Making security an inherent part of development, not an afterthought.

Note: Aims to be secure by design.