Explainer
Read standard input in Python
Use input for prompts, stream lines from sys.stdin, or accept files and pipes with fileinput without accidentally consuming input twice.
Explainer
Remove a key from a Python dictionary
Choose del or pop for dictionary deletion, distinguish a missing key from a stored None, and remove multiple entries without mutating an active iterator.
Explainer
Remove trailing newlines from a Python string
Choose rstrip or removesuffix based on whether you want to remove all trailing newline characters, one line ending, or every kind of whitespace.
Explainer
Reverse a string in Python
Reverse a string with slicing or reversed, and understand why Unicode code-point reversal may split combining marks or emoji sequences.
Explainer
Schedule a Python script with cron
Run a Python script from cron with explicit paths, a predictable environment, writable logs, and checks for failed or missing executions.
Explainer
Sort a list of dictionaries by a field in Python
Sort records with a key function, combine multiple fields, choose missing-value behavior, and preserve stable ordering.
Explainer
Sort a dictionary by keys or values in Python
Create sorted item lists or dictionaries, handle ties and mixed types, and distinguish insertion order from automatic sorted order.
Explainer
Split a Python list into chunks
Use slicing or itertools.batched to process fixed-size groups, validate the chunk size, and distinguish chunk size from number of chunks.
Explainer
Start a local HTTP file server with Python
Serve a directory for local testing with http.server, choose the bind address explicitly, and understand version-specific HTTPS support and exposure limits.
Explainer
Convert strings to uppercase or lowercase in Python
Use Python string case methods, choose casefold for Unicode-aware comparisons, and avoid surprising title-case and whitespace behavior.
Explainer
How do I add fields or routing tags to Fluentd events?
Use record_transformer to enrich Fluentd records, rewrite_tag_filter to route errors, and a tail input tag to identify file events.
Technical guide
Fix Git’s “Another Git process seems to be running” error
Check for an active Git operation before removing a stale lock. Locate the correct lock file, including in linked worktrees, and preserve staged changes.