Thread-safe printing in Python

Recently, a coworker was having issues printing from multiple threads in his python program.

After a little googling, I came upon this discussion which covered this exact topic.

At the lowest level, python appears to be threadsafe wrt a single file handle, which is good. Unfortunately, when you use the print statement, an implicit '\n' is added for you, and this apparently results in a second low-level write call, which is a seperate mutex grab.

As a result, you often get lines of text that look like this:

This text comes from Thread 1.This text comes from Thread2.
< Empty Line >
This text comes from Thread 1.This text comes from Thread2.
< Empty Line >

In this situation, you basically have two choices. You could replace your print statements with a custom written print function that grabs a mutex and adds a trailing '\n', or you could use the logging module. Even though the threadsafe print module is very short, I'd still suggest that the 'right thing' to do here is to just use the logging module.

When you decide in the future that you want to log to a tcp connection on another server, your future self will pat yourself on the back that you just used logging up front.

Cheers,