46.11. Environment Variables
Some of the environment variables that are accepted by the Python interpreter can also be used to affect PL/Python behavior. They would need to be set in the environment of the main PostgreSQL server process, for example in a start script. The available environment variables depend on the version of Python; see the Python documentation for details. At the time of this writing, the following environment variables have an affect on PL/Python, assuming an adequate Python version:
- 
    PYTHONHOME
- 
    PYTHONPATH
- 
    PYTHONY2K
- 
    PYTHONOPTIMIZE
- 
    PYTHONDEBUG
- 
    PYTHONVERBOSE
- 
    PYTHONCASEOK
- 
    PYTHONDONTWRITEBYTECODE
- 
    PYTHONIOENCODING
- 
    PYTHONUSERBASE
- 
    PYTHONHASHSEED
  (It appears to be a Python implementation detail beyond the control
   of PL/Python that some of the environment variables listed on
   the
  
   python
  
  man page are only effective in a
   command-line interpreter and not an embedded Python interpreter.)