Technical guide
Find and restore a deleted file in Git
Locate a deletion commit, restore the file from its parent, stage the recovered file, and distinguish committed deletions from working-tree or index changes.
Technical guide
Find when and by whom a file was deleted in Git
Locate deletion commits, inspect author and committer metadata, recover the previous contents, and choose between restoring one file and reverting a whole commit.
Explainer
Fix “Python.h: No such file or directory”
Find the headers for the Python interpreter building your extension, install matching development packages, and avoid mixing container or interpreter versions.
Explainer
Flatten a nested list in Python
Flatten one level with a comprehension or itertools.chain, and use a list-specific recursive function when the nesting depth varies.
Explainer
Flush Python print output immediately
Use flush=True, stdout.flush(), or unbuffered Python output, and distinguish application buffering from log delivery and durable disk writes.
Technical guide
Make a local Git branch match the remote
Fetch and reset deliberately when remote contents should replace local work, preserve commits and edits first, and preview optional untracked-file cleanup.
Explainer
Configure runtime DNS resolution in Nginx
Refresh changing upstream addresses with resolver and variable proxy_pass, or use dynamic upstream resolution on supported Nginx versions.
Explainer
Redirect HTTP traffic to HTTPS with Nginx
Configure an HTTPS redirect, preserve paths and query strings, make health-check exceptions work, and enable HSTS deliberately.
Technical guide
Remove Git tracking from a directory initialized with git init
Remove a standalone repository’s .git directory while keeping its files, check local-only work first, and distinguish linked worktrees, submodules, and remote deletion.
Explainer
Can you recover a private key from an Nginx certificate?
A certificate cannot reveal its matching private key. Locate a saved key, verify the public-key match, or generate a new key and reissue.
Explainer
Get the class name of a Python instance
Use type(obj).__name__ for an instance’s class name, and add the module and qualified name when a short name is ambiguous.
Explainer
Get the current date and time in Python
Read local or UTC time with datetime, obtain Unix timestamps, and use an elapsed-time clock when measuring how long code runs.