First 3 logs show and then cloudwatch stops showing logs

Question

Hi,  
I am using AWS Batch to run a task which essentially consists of a Python script, which uses "print" statements to log messages. The first three of these (which are fired right after the script starts executing) show up in Cloudwatch. Almost immediately after these three print statements, there should be a fourth, which never shows up in Cloudwatch. Nor do any subsequent print statements. The script is still executing, so the logs should show up, but don't...  
  
Any help is very very much appreciated. Thanks!

Marnixhoh · Answer

Ok I figured out the problem... Turns out that Python was buffering print statements inside of child processes (I am using parallel processing using the multiprocessing module), instead of flushed directly. This behavior of Python is not very obvious, since it does not buffer the print statements when running in a tty.  
  
The fix was to simply supply a flag (-u) to the python command. E.g. python3 -u script.py  
  
In case anyone is interested, more info can be found here: https://stackoverflow.com/questions/107705/disable-output-buffering

First 3 logs show and then cloudwatch stops showing logs

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