[IMP] core: improve python external dependencies check

Use pkg_resources.get_distribution() to check if python external
dependencies are installed, instead of trying an import.
The import test is preserved as a backwards compatibility measure.

This better expresses which python distribution needs to be installed
from PyPI and allows declaring a minimum supported version using PEP 440
version specifiers.

Closes #25541

closes odoo/odoo#25549

Signed-off-by: Christophe Simonis <chs@odoo.com>

addons/auth_ldap/__manifest__.py

@@ -11,6 +11,6 @@
         'views/res_config_settings_views.xml',
     ],
     'external_dependencies' : {
-        'python' : ['ldap'],
+        'python' : ['pyldap'],
     }
 }

addons/hw_blackbox_be/__manifest__.py

@@ -19,6 +19,6 @@ Belgian cash register. It allows the communication on with a certified Fiscal
 Data Module but will not modify the behaviour of the Point of Sale.
 """,
     'depends': ['hw_proxy'],
-    'external_dependencies': {'python': ['serial']},
+    'external_dependencies': {'python': ['pyserial']},
     'installable': False,
 }

addons/hw_escpos/__manifest__.py

@@ -18,7 +18,7 @@ that would need such functionality.
 """,
     'depends': ['hw_proxy'],
     'external_dependencies': {
-        'python' : ['usb.core','serial','qrcode'],
+        'python' : ['pyusb','pyserial','qrcode'],
     },
     'installable': False,
 }

odoo/addons/base/models/ir_module.py

@@ -8,6 +8,7 @@ import importlib
 import io
 import logging
 import os
+import pkg_resources
 import shutil
 import tempfile
 import zipfile
@@ -307,16 +308,33 @@ class Module(models.Model):
         self.clear_caches()
         return super(Module, self).unlink()
 
+    @staticmethod
+    def _check_python_external_dependency(pydep):
+        try:
+            pkg_resources.get_distribution(pydep)
+        except pkg_resources.DistributionNotFound as e:
+            try:
+                importlib.import_module(pydep)
+                _logger.warning("python external dependency %s should be replaced by it's PyPI package name", pydep)
+            except ImportError:
+                # backward compatibility attempt failed
+                _logger.warning("DistributionNotFound: %s", e)
+                raise Exception('Python library not installed: %s' % (pydep,))
+        except pkg_resources.VersionConflict as e:
+            _logger.warning("VersionConflict: %s", e)
+            raise Exception('Python library version conflict: %s' % (pydep,))
+        except Exception as e:
+            _logger.warning("get_distribution(%s) failed: %s", pydep, e)
+            raise Exception('Error finding python library %s' % (pydep,))
+
+
     @staticmethod
     def _check_external_dependencies(terp):
         depends = terp.get('external_dependencies')
         if not depends:
             return
         for pydep in depends.get('python', []):
-            try:
-                importlib.import_module(pydep)
-            except ImportError:
-                raise ImportError('No module named %s' % (pydep,))
+            Module._check_python_external_dependency(pydep)
 
         for binary in depends.get('bin', []):
             try: