Python: Remove one of three filesystem structures

For commands where the entry in python/mrtrix3/commands/ is not a standalone .py file but a directory, previously there were two possible filesystem contents. One was for that sub-directory to contain a .py file with the same name as the command, as determined by the name of the python/commands/ sub-directory, and that file is expected to contain functions called uage() and execute(). The second is for such a file to be absent, but for there to instead exist two files called usage.py and execute.py, which would provide those relevant functions. This commit removes support for the latter.

cmake/MakePythonExecutable.cmake

@@ -17,33 +17,28 @@ set(BINPATH_CONTENTS
     "\n"
 )
 
-# Three possible interfaces:
+# Two possible interfaces:
 #   1. Standalone file residing in commands/
 #   2. File stored in location commands/<cmdname>/<cmdname>.py, which will contain usage() and execute() functions
-#   3. Two files stored at commands/<cmdname>/usage.py and commands/<cmdname>/execute.py, defining the two corresponding functions
 if(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/${CMDNAME}/__init__.py")
-    if(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/${CMDNAME}/usage.py" AND EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/${CMDNAME}/execute.py")
-        string(APPEND BINPATH_CONTENTS
-            "module_usage = importlib.import_module('.usage', 'mrtrix3.commands.${CMDNAME}')\n"
-            "module_execute = importlib.import_module('.execute', 'mrtrix3.commands.${CMDNAME}')\n"
-            "_execute(module_usage.usage, module_execute.execute)\n"
-        )
-    elseif(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/${CMDNAME}/${CMDNAME}.py")
+    if(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/${CMDNAME}/${CMDNAME}.py")
         string(APPEND BINPATH_CONTENTS
             "module = importlib.import_module('.${CMDNAME}', 'mrtrix3.commands.${CMDNAME}')\n"
-            "_execute(module.usage, module.execute)\n"
         )
     else()
         message(FATAL_ERROR "Malformed filesystem structure for Python command ${CMDNAME}")
     endif()
 elseif(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/${CMDNAME}.py")
     string(APPEND BINPATH_CONTENTS
         "module = importlib.import_module('.${CMDNAME}', 'mrtrix3.commands')\n"
-        "_execute(module.usage, module.execute)\n"
     )
 else()
     message(FATAL_ERROR "Malformed filesystem structure for Python command ${CMDNAME}")
 endif()
+string(APPEND BINPATH_CONTENTS
+    "_execute(module.usage, module.execute)\n"
+)
+
 
 if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.19)
     file(WRITE ${OUTPUT_DIR}/${CMDNAME} ${BINPATH_CONTENTS})

python/mrtrix3/commands/population_template/population_template.py

@@ -0,0 +1,23 @@
+# Copyright (c) 2008-2024 the MRtrix3 contributors.
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# Covered Software is provided under this License on an "as is"
+# basis, without warranty of any kind, either expressed, implied, or
+# statutory, including, without limitation, warranties that the
+# Covered Software is free of defects, merchantable, fit for a
+# particular purpose or non-infringing.
+# See the Mozilla Public License v. 2.0 for more details.
+#
+# For more details, see http://www.mrtrix.org/.
+
+from .usage import usage as my_usage
+from .execute import execute as my_execute
+
+def usage(cmdline): #pylint: disable=unused-variable
+  return my_usage(cmdline)
+
+def execute(): #pylint: disable=unused-variable
+  return my_execute()