Extended filenames as dict

Closes #102 (closed)

pyotb/core.py

@@ -776,20 +776,18 @@ class App(OTBObject):
 
         # Append filename extension to filenames
         if ext_fname:
-            assert isinstance(ext_fname, (dict, str))
+            if not isinstance(ext_fname, (dict, str)):
+                raise ValueError("Extended filename must be a str or a dict")
             def _str2dict(ext_str):
                 """Function that converts str to dict."""
-                return dict(
-                    keyval for pair in ext_str.split("&")
-                    if len(keyval := pair.split("=")) == 2
-                )
+                splits = [pair.split("=") for pair in ext_str.split("&")]
+                return dict(split for split in splits if len(split) == 2)
 
-            if isinstance(ext_fname, str):
-                # transform str to dict
-                ext_fname = _str2dict(ext_fname)
+            new_ext_fname = _str2dict(ext_fname) \
+                if isinstance(ext_fname, str) else ext_fname.copy()
 
             logger.debug("%s: extended filename for outputs:", self.name)
-            for key, ext in ext_fname.items():
+            for key, ext in new_ext_fname.items():
                 logger.debug("%s: %s", key, ext)
 
             for key, filepath in kwargs.items():
@@ -798,11 +796,12 @@ class App(OTBObject):
                     if "?&" in filepath:
                         filepath, already_set_ext = filepath.split("?&", 1)
                         # ext_fname prevail over extensions in filepath
-                        ext_fname = {**_str2dict(already_set_ext), **ext_fname}
+                        new_ext_fname.update(_str2dict(already_set_ext))
 
                     # transform dict to str
                     ext_fname_str = "&".join([
-                        f"{key}={value}" for key, value in ext_fname.items()
+                        f"{key}={value}"
+                        for key, value in new_ext_fname.items()
                     ])
                     parameters[key] = f"{filepath}?&{ext_fname_str}"