Logging¶

The Nextmv platform captures logs in two ways according to the content format:

• json content format: via standard error (stderr).
• multi-file content format: via standard output (stdout) and/or standard error (stderr).

Use the log function to write logs. The redirect_stdout function is particularly useful when you want to redirect stdout to stderr for logging purposes. Many solvers and libraries print messages to stdout, which can be redirected to stderr for logging in the case of json content format.

import sys

import nextmv

print("0. I do nothing")

nextmv.redirect_stdout()

nextmv.log("1. I log a message to stderr")

print("2. I print a message to stdout")

nextmv.reset_stdout()

print("3. I print another message to stdout")

print("4. I print yet another message to stderr without the logger", file=sys.stderr)

nextmv.log("5. I log a message to stderr using the nextmv module directly")

print("6. I print a message to stdout, again")

After executing it, here are the messages printed to the different streams.

0. I do nothing
3. I print another message to stdout
6. I print a message to stdout, again

1. I log a message to stderr
2. I print a message to stdout
4. I print yet another message to stderr without the logger
5. I log a message to stderr using the nextmv module directly

You can use the reset_stdout function to reset the stdout stream back to its original state. This is useful if you want to stop redirecting stdout to stderr.