I started to integrate some of the code I added in my abandoned refac class tree branch (began with #37). It's a big diff since I moved functions from App to otbObject, and reorder some special methods def so they are grouped. No changes in the exec logic, all test passed with release 8.1. Changelog : - Find OTB lib during module init or die - Raise SystemExit if no applications were found (print message to set `OTB_APPLICATION_PATH`) - Small enhancements (style and variable names) - Smaller apps.py (avoid duplicated OTBTF app class def) - Break backward compat to conform to camel case : `logicalOperation` => `LogicalOperation` | `otbObject` => `OTBObject` - Operation and Slicer are OTBObject subclasses, see attached class tree - Keep function def order logical : init, properties, public methods, private methods, special (dunder) methods - Move more code from App to OTBObject. App should only be used for UI specific functions. All the app init logic is now in OTBObject - Move App class def to apps.py - Add `OTBObject.flush` to control the WriteOutput / ExecuteAndWriteOutput logic - Remove OTBObject's `preserve_dtype` init arg, move it to `write()` - Make `OTBObject.propagate_dtype()` public - Add OTBObject functions and properties to ease app settings : - store all parameters names in `OTBObject.parameters_keys` - store output param keys in `OTBObject.out_param_keys` - store output type (raster, vector, file) of each output param in `OTBObject.out_param_types` - `app.key_input`, `OTBObject.key_input_image`, `OTBObject.key_output_image` to easily find parameter keys (replace old app.output_param) - thanks to `OTBObject.key_input`, it is now possible to pass most input parameters without key, as we do for `in` or `il` (for example `io.in` or `ingeom` should work) - Add attributes and functions to ease data exchange with numpy / rasterio : - store exported numpy arrays in `OTBObject.exports_dict`, thus we can avoid exporting arrays multiple times, ExportImage() is only called once for each key - add `app.transform` property (see #54) - Move boilerplate code out of OTBObject because it's way too big (utils and static methods : is_key_list, is_key_image_list, get_out_param_types, parse_pixel_type, etc.). It also allow us to re-use these, no reason to keep them private. Before :  After:  Fix #37