Compile

Optimize

-O Turn on basic optimizations. This changes the filename extension for compiled (bytecode) files from .pyc to .pyo. Given twice, causes docstrings to be discarded.

# $ python -h
# -m mod : run library module as a script (terminates option list)
# -O     : optimize generated bytecode slightly; also PYTHONOPTIMIZE=x
# -OO    : remove doc-strings in addition to the -O optimizations

• Default

  In [1]: import sys
  
  In [2]: sys.flags.optimize
  Out[2]: 0
  
  In [3]: __debug__
  Out[3]: True
  

Pyc

• Command-line

  python -m py_compile $filename
  

• Script

  import py_compile
  py_compile.compile('$filename')  # $filename is the file name of python source code.
  

Pyo

• Command-line

  python -O -m py_compile $filename
  python -OO -m py_compile $filename
  

• PEP 488 -- Elimination of PYO files

Compile Dir

import compileall
compileall.compile_dir('$dir')

Alias

###########
# Pyc & Pyo
###########

# [32.10. py_compile — Compile Python source files](https://docs.python.org/2/library/py_compile.html)
alias pyc='python -m py_compile'
alias pyo='python -O -m py_compile'
alias pyo1='python -O -m py_compile'
alias pyo2='python -OO -m py_compile'

# [32.11. compileall — Byte-compile Python libraries](https://docs.python.org/2/library/compileall.html)
alias pycdir='python -m compileall'
alias pyodir='python -O -m compileall'
alias pyo1dir='python -O -m compileall'
alias pyo2dir='python -OO -m compileall'

References

[1] Docs@Python, 32.10. py_compile — Compile Python source files

[2] Docs@Python, 32.11. compileall — Byte-compile Python libraries

[3] Docs@Python, What’s New In Python 3.5 - PEP 488: Elimination of PYO files

[4] Docs@Python, 1. Command line and environment

[5] u0b34a0f6ae@StackOverflow, What is the use of Python's basic optimizations mode? (python -O)

[6] zaharpopov@StackOverflow, python optimized mode

[7] max@StackOverflow, What does Python optimization (-O or PYTHONOPTIMIZE) do?