Python Programming Cheat Sheet
Advanced Python programming reference guide
Python Programming Cheat Sheet
Advanced Python programming concepts and patterns. Click the copy button to copy any command.
91
Total Commands
91
Filtered Results
List Comprehensions
| Command | Copy | Description |
|---|---|---|
[x*2 for x in range(10)] | Basic list comprehension | |
[x for x in range(10) if x % 2 == 0] | List comprehension with condition | |
[x if x > 0 else 0 for x in nums] | List comprehension with if-else | |
[[i*j for j in range(3)] for i in range(3)] | Nested list comprehension | |
[x+y for x in list1 for y in list2] | Multiple iterables |
Dictionary Comprehensions
| Command | Copy | Description |
|---|---|---|
{x: x**2 for x in range(5)} | Basic dict comprehension | |
{k: v for k, v in dict.items() if v > 0} | Dict comprehension with filter | |
{v: k for k, v in dict.items()} | Swap keys and values |
Set Comprehensions
| Command | Copy | Description |
|---|---|---|
{x**2 for x in range(10)} | Basic set comprehension | |
{x for x in list if x > 0} | Set comprehension with filter |
Generator Expressions
| Command | Copy | Description |
|---|---|---|
(x**2 for x in range(10)) | Generator expression | |
sum(x**2 for x in range(10)) | Generator in function |
Lambda Functions
| Command | Copy | Description |
|---|---|---|
lambda x: x*2 | Simple lambda | |
lambda x, y: x + y | Lambda with multiple args | |
lambda x: x if x > 0 else 0 | Lambda with conditional | |
sorted(list, key=lambda x: x[1]) | Lambda as key function |
Map, Filter, Reduce
| Command | Copy | Description |
|---|---|---|
list(map(lambda x: x*2, nums)) | Map with lambda | |
list(filter(lambda x: x > 0, nums)) | Filter with lambda | |
from functools import reduce
reduce(lambda x, y: x+y, nums) | Reduce to sum |
Decorators
| Command | Copy | Description |
|---|---|---|
@decorator
def func():
pass | Basic decorator usage | |
def decorator(func):
def wrapper(*args, **kwargs):
return func(*args, **kwargs)
return wrapper | Define decorator | |
@property | Property decorator | |
@staticmethod | Static method decorator | |
@classmethod | Class method decorator |
Generators
| Command | Copy | Description |
|---|---|---|
def gen():
yield value | Basic generator | |
next(generator) | Get next value from generator | |
yield from iterable | Delegate to sub-generator |
Context Managers
| Command | Copy | Description |
|---|---|---|
with open("file") as f:
data = f.read() | File context manager | |
from contextlib import contextmanager
@contextmanager
def my_context():
yield | Custom context manager |
Classes - Advanced
| Command | Copy | Description |
|---|---|---|
class MyClass:
def __init__(self, x):
self.x = x | Class with constructor | |
class Child(Parent): | Inheritance | |
super().__init__() | Call parent constructor | |
def __str__(self):
return "string" | String representation | |
def __repr__(self):
return "repr" | Object representation | |
def __len__(self):
return length | Length magic method | |
def __getitem__(self, key):
return self.data[key] | Index access | |
@property
def x(self):
return self._x | Getter property | |
@x.setter
def x(self, value):
self._x = value | Setter property |
Data Classes
| Command | Copy | Description |
|---|---|---|
from dataclasses import dataclass
@dataclass
class Point:
x: int
y: int | Define dataclass |
Type Hints
| Command | Copy | Description |
|---|---|---|
def func(x: int) -> int: | Function with type hints | |
from typing import List, Dict, Tuple | Import typing module | |
numbers: List[int] = [1, 2, 3] | List type hint | |
data: Dict[str, int] = {} | Dict type hint | |
from typing import Optional
x: Optional[int] = None | Optional type | |
from typing import Union
x: Union[int, str] | Union type |
Itertools
| Command | Copy | Description |
|---|---|---|
from itertools import chain
chain(list1, list2) | Chain iterables | |
from itertools import combinations
combinations(iterable, r) | Generate combinations | |
from itertools import permutations
permutations(iterable, r) | Generate permutations | |
from itertools import product
product(iter1, iter2) | Cartesian product | |
from itertools import islice
islice(iterable, start, stop) | Slice iterator |
Collections
| Command | Copy | Description |
|---|---|---|
from collections import Counter
Counter(list) | Count elements | |
from collections import defaultdict
defaultdict(int) | Dict with default values | |
from collections import deque
deque([1, 2, 3]) | Double-ended queue | |
from collections import namedtuple
Point = namedtuple("Point", ["x", "y"]) | Named tuple |
String Methods - Advanced
| Command | Copy | Description |
|---|---|---|
s.partition(sep) | Split into 3-tuple | |
s.zfill(width) | Pad with zeros | |
s.center(width) | Center string | |
s.ljust(width) | Left justify | |
s.rjust(width) | Right justify |
List Methods - Advanced
| Command | Copy | Description |
|---|---|---|
list.extend(iterable) | Add all items from iterable | |
list.index(value) | Find index of value | |
list.count(value) | Count occurrences | |
list.copy() | Shallow copy of list | |
list.clear() | Remove all items |
Dictionary Methods - Advanced
| Command | Copy | Description |
|---|---|---|
dict.setdefault(key, default) | Get or set default | |
dict.update(other_dict) | Update with another dict | |
dict.pop(key, default) | Remove and return value | |
dict.popitem() | Remove and return last item | |
{**dict1, **dict2} | Merge dictionaries |
Unpacking
| Command | Copy | Description |
|---|---|---|
*args | Unpack positional arguments | |
**kwargs | Unpack keyword arguments | |
a, *rest = [1, 2, 3, 4] | Unpack with rest | |
a, *middle, b = [1, 2, 3, 4] | Unpack middle values |
Walrus Operator (Python 3.8+)
| Command | Copy | Description |
|---|---|---|
if (n := len(list)) > 10: | Assignment in expression | |
while (line := f.readline()): | Assign and check in loop |
F-strings - Advanced
| Command | Copy | Description |
|---|---|---|
f"{variable=}" | Debug f-string (Python 3.8+) | |
f"{value:.2f}" | Format to 2 decimals | |
f"{value:>10}" | Right align in 10 spaces | |
f"{value:,}" | Thousands separator |
Pathlib
| Command | Copy | Description |
|---|---|---|
from pathlib import Path
Path("file.txt") | Create Path object | |
path.exists() | Check if path exists | |
path.read_text() | Read file as text | |
path.write_text(text) | Write text to file | |
path.glob("*.txt") | Find matching files |
Async/Await
| Command | Copy | Description |
|---|---|---|
async def func():
await operation | Async function | |
asyncio.run(func()) | Run async function | |
await asyncio.gather(*tasks) | Run tasks concurrently |
Error Handling - Advanced
| Command | Copy | Description |
|---|---|---|
raise ValueError("message") | Raise specific exception | |
except (TypeError, ValueError) as e: | Catch multiple exceptions | |
else: | Execute if no exception | |
try:
pass
except Exception:
pass
else:
pass
finally:
pass | Complete try block |
All operations are performed locally in your browser. No data is sent to any server.
About Python Programming Cheat Sheet
This section will contain detailed, SEO-friendly content about the Python Programming Cheat Sheet.
In the future, this content will be managed through a headless CMS, allowing you to:
- Add detailed explanations about how to use this tool
- Include examples and use cases
- Provide tips and best practices
- Add FAQs and troubleshooting guides
- Update content without touching the code
How to Use
Step-by-step instructions for using the Python Programming Cheat Sheet will appear here. This content will be fully customizable through the admin panel.
Features
Key features and benefits of this tool will be listed here. All content is editable via the CMS.