Preferences File

We support an optional file which can be used to alter some internal behavior of XPPython3.

You may create the file <XP>/Output/preferences/xppython3.ini. We use the Main section indicator and support a few flags. Missing values are evaluated as being set to zero where appropriate. For example:

[Main]
debug = 0
flush_log = 1
py_verbose = 0
log_file_name = MyLogFile.txt
log_file_preserve = 0

Flags are:

• debug: when “1”, print loading and initialization progress for all XPPython3 plugins, and provide more detailed warning messages which may help pin-point plugin coding errors. “0” is do not print.

  When this feature is enabled, We also enable the built-in X-Plane error callback, which performs additional run-time error checking and will forward these errors to the python log.

  Recommend keeping this off unless you either don’t appear to be able to load your python plugin, or your plugin crashes yet the printed exception isn’t detailed enough. Otherwise, this options puts a lot of extra noise in the XPPython3Log.txt file, which may make it harder to debug your code.

• flush_log: when “1”, immediately call flush on all writes to XPPython3Log.txt. Normally, calls using xp.log are buffered, for performance reasons. If you’re debugging by following the XPPython3Log.txt file in another window, you’ll not see output until the buffer is flushed. Using the flag will cause your updates to be immediately visible. “0” is do not flush immediately.

  Recommend setting this on during debug. The performance penalty is pretty small, and the immediate flush is very useful.

• py_verbose: This sets the value for PYTHONVERBOSE which is equivalent to the -v python flag. Set to “1”: print a message each time a module (any python module) is initialized, showing the place from which it is loaded. Set to “2”: print a message for each file that is checked for when searching for a module. Also provides information on module cleanup at exit. “0” is do not print.

  Recommend keeping this off unless you just cannot get your plugin loaded, or it appears to be loading the “wrong” file. This generates a lot of log entries.

• log_file_name: This sets the value for the python log file. The default value is XPPython3Log.txt, which will be located in the X-Plane root directory, next to Log.txt. If you set this to a bad value (illegal file, file with incorrect permissions, etc.), python information will be sent to standard output. If you set this value to exactly Log.txt, python information will be added directly to X-Plane’s Log.txt file. This has the advantage of adding python output to the built-in X-Plane Dev Console (with the disadvantage of interspersing python information with all the other X-Plane logging messages.) This parameter is identical to the XPPYTHON3_LOG environment variable. The environment variable, if defined, has precedence.

• log_file_preserve: This controls if the python log file is preserved between invocations. Set to “1” and the file is preserved. Set to “0”, or not set, and the python log file is truncated on startup. This parameter is identical to the XPPYTHON3_PRESERVE environment variable. The environment variable, if defined, has precedence. Note that the environment variable is “true” if it is set to any value, including 0. If you do not which this behavior be sure to unset the environment variable.