Add comment.

Author: purple4reina

Dockerfile

@@ -24,6 +24,12 @@ RUN rm ./python/lib/$runtime/site-packages/ddtrace/internal/datadog/profiling/li
 RUN rm ./python/lib/$runtime/site-packages/ddtrace/internal/datadog/profiling/ddup/_ddup.*.so
 RUN rm ./python/lib/$runtime/site-packages/ddtrace/internal/datadog/profiling/stack_v2/_stack_v2.*.so
 
+# Precompile all .pyc files and remove .py files. This speeds up load time.
+# Compile with optimization level 2 (-o 2) and PYTHONNODEBUGRANGES=1 to redtce
+# size of .pyc files.
+# See https://docs.python.org/3/tutorial/modules.html#compiled-python-files
+# https://docs.python.org/3.11/using/cmdline.html#cmdoption-O
+# https://docs.python.org/3/using/cmdline.html#envvar-PYTHONNODEBUGRANGES
 RUN PYTHONNODEBUGRANGES=1 python -m compileall -o 2 -b ./python/lib/$runtime/site-packages
 RUN find ./python/lib/$runtime/site-packages -name \*.py -delete
 RUN find ./python/lib/$runtime/site-packages -name __pycache__ -type d -exec rm -r {} \+