Python Programming & Syntax Quick Reference Cheatsheet

FREE PDF CHEATSHEET • CLAYI.COM
Python Programming & Syntax
Python quick reference covering data types, control flow, OOP, standard library, and Pythonic patterns.
Python Programming Backend Scripting OOP
Data Types & Collections
int, float, str, bool, None — primitives
list = [1,2,3] — mutable ordered
tuple = (1,2,3) — immutable ordered
set = {1,2,3} — unique unordered
dict = {'k': 'v'} — key-value pairs
type() / isinstance() — type checking
Strings & Comprehensions
f'Hello {name}' — f-string formatting
• str.split(), strip(), join(), replace()
• [x*2 for x in range(10) if x%2==0]
• {k: v for k,v in items.items()}
• str.upper(), lower(), title(), count()
repr() vs str() — developer vs user view
Control Flow & Functions
if / elif / else — conditionals
• for item in iterable / while condition:
break, continue, pass — loop control
def func(*args, **kwargs): — definition
return, yield — return vs generator
lambda x: x*2 — anonymous function
OOP — Classes
class Dog(Animal): — inheritance
• def __init__(self, name): self.name = name
@staticmethod — no self/cls
@classmethod — cls as first arg
@property — getter as attribute
__str__, __repr__, __len__ — dunder methods
Error Handling & Files
• try: / except ValueError as e: / finally:
raise ValueError('msg') — raise exception
with open('f.txt','r') as f: — context mgr
• f.read(), f.readlines(), f.write()
• import json; json.load(f) / json.dump(d,f)
pathlib.Path('file').exists() — modern paths
Built-ins & Standard Library
• map(), filter(), zip(), enumerate()
• sorted(key=lambda x: x[1], reverse=True)
• os.path, os.environ, os.getcwd()
sys.argv, sys.exit() — CLI & exit
datetime.now(), timedelta — time ops
re.match(), re.findall() — regex
More free cheatsheets at clayi.com