performance_tools 0.3

Context Managers

DisplayElapsed

This context manager makes it easy to display console-oriented start/end messages with end-user tolerable formatting.

Usage:

with DisplayElapsed("{now} uploading {filename} (original: {original})\n",
                    "{now} uploaded {filename} in {elapsed:.1f} seconds",
                    filename=remote_path, original=local_path):
    upload_filename(…)

Notes:

• DisplayElapsed takes one positional argument: message. The message is formatted using str.format with the values {now} and {elapsed} provided automatically. All other keyword arguments provided to DisplayElapsed will be available during formatting.

• If message contains {{now}} it will be replaced with the current timestamp

• If message does not contain {{now}} it will be prepended unless include_timestamp=False

• If postamble is not specified, it will default to " ({elapsed:.1f} seconds)"

• If output is not specified, it will default to sys.stdout

• If output_on_error is not True, the normal postamble display will be suppressed when an exception occurs

• By default, a newline will not be emitted after the opening message so the message and postamble will be displayed on a single line. output will be flushed, if supported, to provide immediate feedback. Provide a message which ends in \n if you want multi-line output.