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Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.
How to Convert Data to Strings in Python
Convert common data types like bytes, numbers, containers, and None to readable strings with a safe helper function.
def to_str(value):
"""Convert common types to a readable string, safe for beginners."""
if isinstance(value, bytes):
return value.decode("utf-8")
if isinstance(value, (dict, list, tuple, set)):
return str(value)
if value is None:
return ""
return str(value)
if __name__ == …How to Encode and Decode UTF-8 in Python
Convert a Python string to UTF-8 bytes with .encode() and back to text with .decode(), with a simple demo function.
def encode_decode_demo(text: str):
encoded = text.encode("utf-8")
decoded = encoded.decode("utf-8")
print(f"Original string: {text}")
print(f"Encoded bytes: {encoded}")
print(f"Decoded string: {decoded}")
print(f"Match: {text == decoded}")
if __name__ == "__main__":
encode_decode_demo("Hel…How to Check Disk Free Space in Python with shutil.disk_usage
This Python script uses the standard library shutil.disk_usage to report total, used, and free disk space in bytes, plus a percentage usage figure.
import shutil
def check_disk_free_space(path="/"):
"""Return a tuple of total, used, and free disk space in bytes."""
usage = shutil.disk_usage(path)
return usage.total, usage.used, usage.free
if __name__ == "__main__":
total, used, free = check_disk_free_space()
print(f"Total: {total:,} bytes"…How to Compress a String to Gzip Bytes in Python
Compress a string into gzip-compressed bytes entirely in memory using the standard library gzip module.
import gzip
def compress_to_gzip_bytes(data: str, encoding: str = "utf-8") -> bytes:
"""Compress a string to gzip-compressed bytes in memory."""
return gzip.compress(data.encode(encoding))
if __name__ == "__main__":
original = "Hello, world! " * 10
compressed = compress_to_gzip_bytes(original)
pr…How to Read Binary File Bytes and Inspect the Header in Python
Read the first bytes of a binary file with pathlib and display them as a hex dump plus an ASCII view to inspect file headers.
import pathlib
def inspect_binary_header(filepath: str, num_bytes: int = 16) -> None:
"""Read the first bytes of a binary file and display them as hex and ASCII."""
path = pathlib.Path(filepath)
data = path.read_bytes()[:num_bytes]
hex_str = ' '.join(f"{byte:02x}" for byte in data)
ascii_str …How to Serialize a Python Object to Pickle Bytes in Memory
Serialize a Python object to pickle bytes in memory with pickle.dumps, then deserialize it back with pickle.loads and verify the roundtrip.
import pickle
class Person:
def __init__(self, name, age, skills):
self.name = name
self.age = age
self.skills = skills
def main():
person = Person("Alice", 30, ["Python", "SQL", "Docker"])
# Serialize to bytes in memory
pickle_bytes = pickle.dumps(person)
print(…How to Write Bytes to a File in Python with 'wb'
Write a bytearray buffer to a binary file using Python's open() in 'wb' mode, then read it back to confirm the data.
data = bytearray([0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x20, 0x57, 0x6f, 0x72, 0x6c, 0x64])
with open("output.bin", "wb") as f:
f.write(data)
with open("output.bin", "rb") as f:
content = f.read()
print(f"Written {len(data)} bytes: {content}")
print(f"As string: {content.decode('ascii')}")Reassemble File Parts into Original File Bytes in Python
Read sorted part files from a directory and concatenate their bytes into the original file.
import os
import sys
from pathlib import Path
def reassemble_parts(parts_dir: Path, output_path: Path) -> int:
"""
Reassemble file parts into the original file.
Args:
parts_dir: Directory containing the part files
output_path: Path where the reassembled file will be written
Returns:
…Create Mock Watermarked Image Bytes in Python Without PIL
Builds a mock image-like byte stream with an embedded watermark using only stdlib modules, for testing pipelines without PIL.
from io import BytesIO
import zlib
import struct
def create_watermarked_bytes(width: int, height: int, watermark: bytes) -> bytes:
"""Create a mock image-like byte stream with a watermark (no PIL)."""
header = struct.pack("<2I", width, height)
payload = watermark * max(1, (width * height // max(1, len(wa…How to Merge PDFs in Python (Mock pypdf Stub)
Merge PDF files by concatenating their raw byte content using a simple stubbed class that mimics the pypdf interface.
import io
from hashlib import sha256
class PdfStub:
def __init__(self, data: bytes, name: str):
self.data = data
self.name = name
def get_content_bytes(self) -> bytes:
return self.data
def merge_pdfs_mock(pdf_stubs) -> bytes:
merged = io.BytesIO()
for stub in pdf_stubs:
…How to Strip EXIF Metadata from Images in Python
Remove EXIF metadata from image bytes using Pillow, with a mock JPEG generator for testing.
from PIL import Image
from PIL.ExifTags import TAGS
from io import BytesIO
import struct
def strip_exif(image_bytes, remove_metadata=True):
"""Remove EXIF metadata from image bytes."""
img = Image.open(BytesIO(image_bytes))
if remove_metadata:
# Clear all metadata
img.info.clear()
# Sa…How to Use Array Typecodes for Compact Numeric Storage in Python
This code demonstrates how to use the `array` module with typecodes to store integers, floats, and bytes in a memory-efficient way compared to standard Python lists.
from array import array
def demonstrate_array_types():
# Compact integer arrays
small_ints = array('i', [1, 2, 3, 4, 5])
unsigned_ints = array('I', [10, 20, 30])
# Floating point arrays
floats = array('f', [1.5, 2.5, 3.5])
doubles = array('d', [1.123456789, 2.987654321])
# Charac…Fuzz Test Random Bytes Input Crash in Python
A simple fuzz test generates random byte inputs and runs a parser to find unexpected crashes.
import random
def parse_header(data: bytes) -> dict:
"""Parse a fake binary header format."""
if len(data) < 8:
raise ValueError("header too short")
magic = data[:4]
if magic != b'PARS':
raise ValueError("bad magic")
version = data[4]
if version != 1:
raise ValueErro…How to Encode and Decode Avro Data in Python (Roundtrip)
Serialize a Python dict to Avro binary bytes and decode it back using the fastavro-compatible avro library.
import io
import json
from avro.schema import parse
from avro.io import DatumWriter, DatumReader, BinaryEncoder, BinaryDecoder
def avro_roundtrip(schema_json, data):
schema = parse(json.dumps(schema_json))
bytes_writer = io.BytesIO()
encoder = BinaryEncoder(bytes_writer)
writer = DatumWriter(schema)
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Copy-ready Python snippets for learners and developers
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Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.