Setting LD_LIBRARY_PATH from inside Python

Your script can check for the existence/properness of the environment variable before you import your module, then set it in os.environ if it is missing, and then call os.execv() to restart the python interpreter using the same command line arguments but an updated set of environment variables.

This is only advisable before any other imports (other than os and sys), because of potential module-import side-effects, like opened file descriptors or sockets, which may be challenging to close cleanly.

This code sets LD_LIBRARY_PATH and ORACLE_HOME:

#!/usr/bin/python
import os, sys
if 'LD_LIBRARY_PATH' not in os.environ:
    os.environ['LD_LIBRARY_PATH'] = '/usr/lib/oracle/XX.Y/client64/lib'
    os.environ['ORACLE_HOME'] = '/usr/lib/oracle/XX.Y/client64'
    try:
        os.execv(sys.argv[0], sys.argv)
    except Exception, exc:
        print 'Failed re-exec:', exc
        sys.exit(1)
#
# import yourmodule
print 'Success:', os.environ['LD_LIBRARY_PATH']
# your program goes here

It’s probably cleaner to set that environment variable as part of the starting environment (in the parent process or systemd/etc job file).

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