Print and Comments
You will study Print and Comments. It belongs to the Foundations phase. Remember this: Python executes line by line and print shows the current …
PYTHON COURSE
Learn Python step by step
Each topic has simple notes, example code, and one challenge. You run Python in your browser. When your output passes the checks, you unlock the next topic.
7 phases
63 topics
Challenges with checks
How to use this course
- Open a topic card. Read the notes and the example code.
- Do the challenge in the editor and click Run.
- Finish one topic to unlock the next. Cards show Locked, Open, or Completed.
- The course checks your output so you know you really solved the task.
All Topic Cards
Course progress: 0/63
Variables
Variables is used in many real programs. Right now you are in Foundations. Core idea: A variable is a named box storing data. Read …
Data Types
This lesson is about Data Types. You are in the Foundations part of the course. Main idea: Python tracks the type of each value …
Type Casting
You will study Type Casting. It belongs to the Foundations phase. Remember this: Casting converts values into the required data type. Practice step by …
Operators
Operators is used in many real programs. Right now you are in Foundations. Core idea: Operators tell Python what operation to perform between values. …
Comparison Operators
This lesson is about Comparison Operators. You are in the Foundations part of the course. Main idea: Comparisons evaluate to True or False. How …
Logical Operators
You will study Logical Operators. It belongs to the Foundations phase. Remember this: Logical operators combine multiple True/False conditions. Practice step by step. Do …
User Input
User Input is used in many real programs. Right now you are in Foundations. Core idea: input() always returns text unless converted. Read the …
if/else
This lesson is about if/else. You are in the Logic part of the course. Main idea: if chooses one path based on condition result. …
elif Ladder
You will study elif Ladder. It belongs to the Logic phase. Remember this: elif checks additional conditions when previous ones fail. Practice step by …
Nested Conditions
Nested Conditions is used in many real programs. Right now you are in Logic. Core idea: A condition can contain another decision layer. Read …
match/case
This lesson is about match/case. You are in the Logic part of the course. Main idea: match routes execution by exact pattern/value. How to …
while Loop
You will study while Loop. It belongs to the Logic phase. Remember this: while repeats until condition becomes False. Practice step by step. Do …
for Loop
for Loop is used in many real programs. Right now you are in Logic. Core idea: for iterates over each item in a sequence. …
break and continue
This lesson is about break and continue. You are in the Logic part of the course. Main idea: break exits loop; continue skips current …
Loop else
You will study Loop else. It belongs to the Logic phase. Remember this: else runs if loop completes without break. Practice step by step. …
try/except
try/except is used in many real programs. Right now you are in Logic. Core idea: Exceptions jump control to except blocks. Read the example …
finally and raise
This lesson is about finally and raise. You are in the Logic part of the course. Main idea: finally runs no matter what; raise …
Lists
You will study Lists. It belongs to the Data Mastery phase. Remember this: Lists are ordered mutable collections. Practice step by step. Do not …
List Methods
List Methods is used in many real programs. Right now you are in Data Mastery. Core idea: Methods modify list state. Read the example …
List Comprehension
This lesson is about List Comprehension. You are in the Data Mastery part of the course. Main idea: Comprehension builds a new list from …
Tuples
You will study Tuples. It belongs to the Data Mastery phase. Remember this: Tuples are ordered immutable collections. Practice step by step. Do not …
Sets
Sets is used in many real programs. Right now you are in Data Mastery. Core idea: Sets store unique unordered values. Read the example …
Set Operations
This lesson is about Set Operations. You are in the Data Mastery part of the course. Main idea: Set math finds overlaps and differences …
Dictionaries
You will study Dictionaries. It belongs to the Data Mastery phase. Remember this: Dictionary maps keys to values. Practice step by step. Do not …
Dictionary Methods
Dictionary Methods is used in many real programs. Right now you are in Data Mastery. Core idea: Methods update and query key-value data efficiently. …
Nested Structures
This lesson is about Nested Structures. You are in the Data Mastery part of the course. Main idea: Lists and dicts can nest to …
Slicing
You will study Slicing. It belongs to the Data Mastery phase. Remember this: Slicing takes a window from sequence using start:stop:step. Practice step by …
Functions
Functions is used in many real programs. Right now you are in Functional Programming. Core idea: Functions package reusable logic. Read the example code …
Parameters and Return
This lesson is about Parameters and Return. You are in the Functional Programming part of the course. Main idea: Parameters are inputs; return gives …
Scope (LEGB)
You will study Scope (LEGB). It belongs to the Functional Programming phase. Remember this: Python resolves names in Local, Enclosing, Global, Builtin order. Practice …
Lambda
Lambda is used in many real programs. Right now you are in Functional Programming. Core idea: Lambda is a small anonymous one-expression function. Read …
map/filter/reduce
This lesson is about map/filter/reduce. You are in the Functional Programming part of the course. Main idea: Functional tools transform streams of values. How …
*args
You will study *args. It belongs to the Functional Programming phase. Remember this: args collects extra positional inputs as tuple. Practice step by step. …
**kwargs
**kwargs is used in many real programs. Right now you are in Functional Programming. Core idea: kwargs collects named inputs as dictionary. Read the …
Closures
This lesson is about Closures. You are in the Functional Programming part of the course. Main idea: Inner function remembers outer scope variables. How …
Classes and Objects
You will study Classes and Objects. It belongs to the Object-Oriented Programming phase. Remember this: Class defines structure; object is concrete instance. Practice step …
__init__ Constructor
__init__ Constructor is used in many real programs. Right now you are in Object-Oriented Programming. Core idea: init runs when creating new object. Read …
Class vs Instance Attributes
This lesson is about Class vs Instance Attributes. You are in the Object-Oriented Programming part of the course. Main idea: Class attrs shared by …
Instance Methods
You will study Instance Methods. It belongs to the Object-Oriented Programming phase. Remember this: Methods operate on object state through self. Practice step by …
Inheritance
Inheritance is used in many real programs. Right now you are in Object-Oriented Programming. Core idea: Child class reuses and extends parent behavior. Read …
Method Overriding
This lesson is about Method Overriding. You are in the Object-Oriented Programming part of the course. Main idea: Child can replace inherited method behavior. …
Polymorphism
You will study Polymorphism. It belongs to the Object-Oriented Programming phase. Remember this: Different classes respond to same method name differently. Practice step by …
Encapsulation
Encapsulation is used in many real programs. Right now you are in Object-Oriented Programming. Core idea: Hide internal state and expose controlled access. Read …
Abstraction
This lesson is about Abstraction. You are in the Object-Oriented Programming part of the course. Main idea: Expose what to do, hide how it …
Dataclasses
You will study Dataclasses. It belongs to the Object-Oriented Programming phase. Remember this: Dataclass auto-generates boilerplate for data containers. Practice step by step. Do …
Iterators
Iterators is used in many real programs. Right now you are in Advanced Engineering. Core idea: Iterator yields one item at a time via …
Generators
This lesson is about Generators. You are in the Advanced Engineering part of the course. Main idea: Generator yields lazily and remembers state between …
Decorators
You will study Decorators. It belongs to the Advanced Engineering phase. Remember this: Decorator wraps a function to add behavior before/after. Practice step by …
Recursion
Recursion is used in many real programs. Right now you are in Advanced Engineering. Core idea: Function solves smaller version of itself until base …
Context Managers
This lesson is about Context Managers. You are in the Advanced Engineering part of the course. Main idea: with ensures setup and cleanup around …
Regular Expressions
You will study Regular Expressions. It belongs to the Advanced Engineering phase. Remember this: Regex is pattern matching for text. Practice step by step. …
Modules and Packages
Modules and Packages is used in many real programs. Right now you are in Advanced Engineering. Core idea: Modules split code into reusable files. …
Logging
This lesson is about Logging. You are in the Advanced Engineering part of the course. Main idea: Logs capture runtime events by severity levels. …
Multithreading Basics
You will study Multithreading Basics. It belongs to the Advanced Engineering phase. Remember this: Threads run tasks concurrently, best for I/O waits. Practice step …
Asyncio Basics
Asyncio Basics is used in many real programs. Right now you are in Advanced Engineering. Core idea: Async tasks cooperate via event loop and …
Virtual Environments
This lesson is about Virtual Environments. You are in the Real-World Tools part of the course. Main idea: Virtual env isolates project dependencies. How …
pip and requirements
You will study pip and requirements. It belongs to the Real-World Tools phase. Remember this: requirements.txt captures dependency versions for reproducibility. Practice step by …
File Handling
File Handling is used in many real programs. Right now you are in Real-World Tools. Core idea: Files are streams read/written in modes. Read …
JSON
This lesson is about JSON. You are in the Real-World Tools part of the course. Main idea: JSON represents structured data as text. How …
REST APIs
You will study REST APIs. It belongs to the Real-World Tools phase. Remember this: API request sends input and receives structured response. Practice step …
NumPy Basics
NumPy Basics is used in many real programs. Right now you are in Real-World Tools. Core idea: NumPy arrays support fast vectorized math. Read …
Pandas Basics
This lesson is about Pandas Basics. You are in the Real-World Tools part of the course. Main idea: DataFrame is table-like structure for analysis. …