Add support for PyInstaller bundle

The embedded Python interpreter is in different path in PyInstaller
bundles than in cx_Freeze ones.

spine_engine/config.py

@@ -34,12 +34,38 @@ def _executable(name):
 JULIA_EXECUTABLE = _executable("julia")
 
 # Python
+def is_frozen():
+    """Checks if we are currently running as frozen bundle.
+
+    Returns:
+        bool: True if we are frozen, False otherwise
+    """
+    return getattr(sys, "frozen", False)
+
+
+def is_pyinstaller_bundle():
+    """Checks if we are in a PyInstaller bundle.
+
+    Returns:
+        bool: True if the current bundle has been build by PyInstaller, False otherwise
+    """
+    return hasattr(sys, "_MEIPASS")
+
+
 PYTHON_EXECUTABLE = _executable("python" if _on_windows else "python3")
 _frozen = getattr(sys, "frozen", False)
 _path_to_executable = os.path.dirname(sys.executable if _frozen else __file__)
 APPLICATION_PATH = os.path.realpath(_path_to_executable)
-# Experimental Python interpreter shipped with Spine Toolbox installation bundle
-EMBEDDED_PYTHON = os.path.join(APPLICATION_PATH, "tools", "python.exe")
+# Python interpreter shipped with bundle
+BUNDLE_DIR = "Python"
+if is_frozen():
+    if is_pyinstaller_bundle():
+        EMBEDDED_PYTHON = os.path.join(sys._MEIPASS, BUNDLE_DIR, PYTHON_EXECUTABLE)
+    else:
+        EMBEDDED_PYTHON = os.path.join(APPLICATION_PATH, BUNDLE_DIR, PYTHON_EXECUTABLE)
+else:
+    EMBEDDED_PYTHON = None
+
 
 # Tool output directory name
 TOOL_OUTPUT_DIR = "output"

spine_engine/utils/helpers.py

@@ -25,7 +25,7 @@
 import networkx
 from jupyter_client.kernelspec import find_kernel_specs
 from spinedb_api.spine_io.gdx_utils import find_gams_directory
-from ..config import PYTHON_EXECUTABLE, JULIA_EXECUTABLE, GAMS_EXECUTABLE, EMBEDDED_PYTHON
+from ..config import is_frozen, PYTHON_EXECUTABLE, JULIA_EXECUTABLE, GAMS_EXECUTABLE, EMBEDDED_PYTHON
 
 
 @unique
@@ -120,7 +120,7 @@ def resolve_python_interpreter(python_path):
     """
     if python_path != "":
         return python_path
-    if not getattr(sys, "frozen", False):
+    if not is_frozen():
         return sys.executable  # Use current Python
     # We are frozen
     path = resolve_executable_from_path(PYTHON_EXECUTABLE)