95 articles tagged #Python
Ran ALTER TABLE on your SQLite database and now your Python queries are returning wrong values or old column names? This is a classic schema-cache and cursor reuse problem — here's exactly how to fix it.
Copying rows between Excel workbooks with openpyxl looks straightforward until you notice fonts, fills, and borders vanishing silently. Learn exactly why styles get dropped and how to copy them reliably.
Getting "Excel xlsx file; not supported" after upgrading xlrd? Since xlrd 2.0 removed support for xlsx files, many Python scripts suddenly broke. Learn why this happens, how to fix it using openpyxl, and the best approaches for reading modern Excel files in Python.
You committed new rows to an SQLite database, queried it right after, and the old data came back. This is a classic isolation and connection-caching trap in Python's sqlite3 module — here's exactly how to fix it.
Run your Python sqlite3 script twice and suddenly your database has double the rows. This guide explains exactly why duplicates happen and gives you battle-tested strategies to stop them permanently.
You've set a number format in openpyxl, saved the file, opened it in Excel — and the cells still look plain. Here's exactly why that happens and how to fix it for currencies, dates, percentages, and more.
Async applications can appear responsive until a hidden deadlock causes tasks to wait forever. Learn how asyncio deadlocks happen, how to detect them early, and how to prevent application freezes in production.
Your openpyxl script runs without errors, but the data lands on the wrong sheet tab — or worse, a brand-new sheet you never asked for. Here's exactly why it happens and how to fix it for good.
Learn why NumPy broadcasting mismatches can produce silently incorrect calculations, how broadcasting rules work, and practical techniques for detecting and preventing costly data processing errors.
openpyxl is returning the formula string like '=SUM(A1:A10)' instead of the calculated result? You're not alone. This guide explains exactly why it happens and shows every reliable fix.
Gadget chain attacks turn your own trusted libraries into remote code execution weapons. Learn how insecure deserialization works, what makes a gadget chain dangerous, and exactly how to harden your code before an attacker finds the gap.
Django REST Framework (DRF) makes it easy to build powerful APIs, but performance issues can quickly emerge as your application grows. Slow database queries, inefficient serializers, missing indexes, and lack of caching can significantly impact API response times and user experience.