Move not_installed_error into utils

connexion/__init__.py

@@ -10,20 +10,12 @@
 from .operations import compat
 from .problem import problem  # NOQA
 from .resolver import Resolution, Resolver, RestyResolver  # NOQA
+from .utils import not_installed_error  # NOQA
 
 full_name = '{}.operation'.format(__package__)
 sys.modules[full_name] = sys.modules[compat.__name__]
 
 
-def not_installed_error(exc):  # pragma: no cover
-    import functools
-
-    def _required_lib(exc, *args, **kwargs):
-        raise exc
-
-    return functools.partial(_required_lib, exc)
-
-
 try:
     from flask import request  # NOQA
 

connexion/security/__init__.py

@@ -4,15 +4,7 @@
 from .async_security_handler_factory import AbstractAsyncSecurityHandlerFactory  # NOQA
 from .security_handler_factory import AbstractSecurityHandlerFactory  # NOQA
 
-
-def not_installed_error(exc):  # pragma: no cover
-    import functools
-
-    def _required_lib(exc, *args, **kwargs):
-        raise exc
-
-    return functools.partial(_required_lib, exc)
-
+from ..utils import not_installed_error
 
 # concrete
 try:

connexion/utils.py

@@ -247,3 +247,12 @@ def ignore_aliases(self, *args):
     yaml.representer.SafeRepresenter.represent_scalar = my_represent_scalar
 
     return yaml.dump(openapi, allow_unicode=True, Dumper=NoAnchorDumper)
+
+
+def not_installed_error(exc):  # pragma: no cover
+    """Raises the ImportError when the module/object is actually called."""
+
+    def _required_lib(exc, *args, **kwargs):
+        raise exc
+
+    return functools.partial(_required_lib, exc)