Python Beginner to Advanced Cheat Sheet

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Print Function

Basic output: print() function displays text
Multiple values: Separate with commas
String format­ting: Use f-strings, format(), or % format­ting.

Indent­ation

Critical in Python - Defines code blocks
Use 4 spaces - Standard convention
Consistent indent­ation - All lines in same block must have same indent­ation

Definition

• def keyword: Define function
• Parame­ters: Input values
• Return: Output value
• Docstr­ings: Docume­ntation

Arguments

• Positi­onal: Order matters
• Keyword: Use parameter names
• Default: Provide default values
• Variable: args, kwargs

Types

• Built-in: print(), len(), type()
• User-d­efined: Custom functions
• Lambda: Anonymous functions
• Generator: Uses yield

Scope*

• Local: Inside function
• Global: Outside functions
• global: Modify global vars
• nonlocal: Enclosing scope

Essential

• print(): Output to console
• input(): Get user input
• len(): Sequence length
• type(): Object type
• isinst­ance(): Check type

Conversion

• int(), float(), str()
• list(), tuple(), set()
• ord(), chr(): Char conversion

Mathem­atical

• abs(): Absolute value
• round(): Round numbers
• min(), max(): Extremes
• sum(): Sequence sum
• pow(): Power calcul­ation

Sequence

• range(): Number sequences
• enumer­ate(): Add indices
• zip(): Combine iterables
• sorted(): Sort sequence
• all(), any(): Boolean ops

Operations

• open(): Open file for I/O
• Modes: '­r', '­w', '­a', '­x'
• Text/B­inary: '­t', '­b' modes
• close(): Close file

Reading

• read(): Entire file
• readli­ne(): Single line
• readli­nes(): All lines
• Iteration: Loop through lines

Writing

write(): Write string
writel­ines(): Write list
Context manager: with statement

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Classes and Objects

• class keyword – Define class
• Object instan­tiation – Create instances
• Instance variables – Data unique to each object
• Class variables – Data shared by all instances
• self parameter – Reference to current instance

Methods

• Instance methods – Access instance data
• Class methods – Work with class data (@clas­sme­thod)
• Static methods – Indepe­ndent functions (@stat­icm­ethod)
• Special methods – init, str, repr, etc.

Inheri­tance

• Parent class – Base class being inherited
• Child class – A class that inherits
• super() function – Access parent class methods
• Method overriding – Redefine parent methods
• Multiple inheri­tance – Inherit from multiple classes

Encaps­ulation

• Private attributes – Prefix with unders­core(s)
• Property decorator – Create getter­/setter methods
• Name mangling – Double underscore prefix
• Public interface – Methods meant for external use

Polymo­rphism

• Same interface, different implem­ent­ations
• Duck typing – "If it looks like a duck..."
• Method overlo­ading – Not directly supported
• Operator overlo­ading – Define behavior for operators

Lists

• Ordered, mutable, duplicates OK
• Methods: append(), insert(), remove()
• Access: indexing [0], slicing [1:3]
• Sort: sort(), reverse()

Tuples

• Ordered, immutable, duplicates OK
• Methods: count(), index()
• Packin­g/U­npa­cking: Multiple assignment
• Faster than lists

Dictio­naries

• Key-value pairs, mutable
• Methods: get(), keys(), values()
• Access: dict[key] or dict.g­et(key)
• Update: update(), pop()

Sets

• Unordered, unique elements
• Methods: add(), remove(), union()
• Operat­ions: inters­ection, difference
• Member­ship: fast in testing

Web Develo­pment

• Backend APIs – RESTful services, GraphQL
• Full-stack frameworks – Django, FastAPI
• Micros­ervices – Flask, FastAPI
• Content management – Django CMS, Wagtail

Data Science & Analytics

• Data analysis – Pandas, NumPy
• Machine learning – Scikit­-learn, Tensor­Flow, PyTorch
• Data visual­isation – Matplo­tlib, Seaborn, Plotly
• Big data – PySpark, Dask

Automation & Scripting

• System admini­str­ation – Automate server tasks
• Web scraping – Beauti­ful­Soup, Scrapy
• Task automation – Schedule, monitor processes
• DevOps tools – Ansible, Fabric

Scientific Computing

• Research computing - SciPy ecosystem
• Bioinf­orm­atics – BioPython
• Astronomy – AstroPy
• Physics simula­tions – NumPy, SciPy

Game Develo­pment

• Pygame – 2D game develo­pment
• Panda3D – 3D game engine
• Game scripting – Embed Python in games
• Game tools – Level editors, asset pipelines

Official Docume­ntation

• python.org – Official Python docume­ntation
• PEP documents – Python Enhanc­ement Proposals
• Library reference – Standard library docume­ntation
• Language reference – Complete language specif­ication

Online Tutorials

• W3Schools
• Python.org tutorial
• Real Python
• Codecademy

Practice Platforms

• LeetCode – Coding interview prepar­ation
• HackerRank – Progra­mming challenges
• Codewars – Coding kata and challenges
• Project Euler – Mathem­atical progra­mming problems