Consistently return DaqNotFoundError when NI-DAQmx is not installed o…

…n all platforms (#433)

CHANGELOG.md

@@ -23,7 +23,10 @@ All notable changes to this project will be documented in this file.
 * ### Merged Pull Requests
     * ...
 * ### Major Changes
-    * ...
+    * `nidaqmx.errors.DaqNotFoundError`, `nidaqmx.errors.DaqNotSupportedError`, and
+    `nidaqmx.errors.DaqFunctionNotSupportedError` are now public exceptions.
+    * Consistently return `nidaqmx.errors.DaqNotFoundError` on all platforms when the NI-DAQmx
+    driver is not installed.
 * ### Known Issues
     * ...
 

generated/nidaqmx/_lib.py

@@ -6,19 +6,17 @@
 import threading
 from typing import cast
 
-from nidaqmx.errors import Error
+from nidaqmx.errors import DaqNotFoundError, DaqNotSupportedError, DaqFunctionNotSupportedError
 
 
-class DaqNotFoundError(Error):
-    pass
+_DAQ_NOT_FOUND_MESSAGE = "Could not find an installation of NI-DAQmx. Please ensure that NI-DAQmx " \
+                         "is installed on this machine or contact National Instruments for support."
 
+_DAQ_NOT_SUPPORTED_MESSAGE = "NI-DAQmx Python is not supported on this platform: {0}. Please " \
+                             "direct any questions or feedback to National Instruments."
 
-class DaqFunctionNotSupportedError(Error):
-    pass
-
-
-class InvalidHandleError(Error):
-    pass
+_FUNCTION_NOT_SUPPORTED_MESSAGE = "The NI-DAQmx function \"{0}\" is not supported in this version " \
+                                  "of NI-DAQmx. Visit ni.com/downloads to upgrade."
 
 
 class c_bool32(ctypes.c_uint):
@@ -95,10 +93,7 @@ def __getattr__(self, function):
                         cfunc.arglock = threading.Lock()
             return cfunc
         except AttributeError:
-            raise DaqFunctionNotSupportedError(
-                'The NI-DAQmx function "{}" is not supported in this '
-                'version of NI-DAQmx. Visit ni.com/downloads to upgrade your '
-                'version of NI-DAQmx.'.format(function))
+            raise DaqFunctionNotSupportedError(_FUNCTION_NOT_SUPPORTED_MESSAGE.format(function))
 
 
 class DaqLibImporter:
@@ -147,28 +142,24 @@ def _import_lib(self):
         cdll = None
 
         if sys.platform.startswith('win') or sys.platform.startswith('cli'):
-            if 'iron' in platform.python_implementation().lower():
-                windll = ctypes.windll.nicaiu
-                cdll = ctypes.cdll.nicaiu
-            else:
-                windll = ctypes.windll.LoadLibrary('nicaiu')
-                cdll = ctypes.cdll.LoadLibrary('nicaiu')
-
+            try:
+                if 'iron' in platform.python_implementation().lower():
+                    windll = ctypes.windll.nicaiu
+                    cdll = ctypes.cdll.nicaiu
+                else:
+                    windll = ctypes.windll.LoadLibrary('nicaiu')
+                    cdll = ctypes.cdll.LoadLibrary('nicaiu')
+            except (OSError, WindowsError) as e:
+                raise DaqNotFoundError(_DAQ_NOT_FOUND_MESSAGE) from e
         elif sys.platform.startswith('linux'):
             # On linux you can use the command find_library('nidaqmx')
             if find_library('nidaqmx') is not None:
                 cdll = ctypes.cdll.LoadLibrary(find_library('nidaqmx'))
                 windll = cdll
             else:
-                raise DaqNotFoundError(
-                    'Could not find an installation of NI-DAQmx. Please '
-                    'ensure that NI-DAQmx is installed on this machine or '
-                    'contact National Instruments for support.')
+                raise DaqNotFoundError(_DAQ_NOT_FOUND_MESSAGE)
         else:
-            raise DaqNotFoundError(
-                'NI-DAQmx Python is not supported on this platform: {}. '
-                'Please direct any questions or feedback to National '
-                'Instruments.'.format(sys.platform))
+            raise DaqNotSupportedError(_DAQ_NOT_SUPPORTED_MESSAGE.format(sys.platform))
 
         self._windll = DaqFunctionImporter(windll)
         self._cdll = DaqFunctionImporter(cdll)
@@ -184,7 +175,7 @@ def _get_task_handle_type(driver_version):
 
     def _parse_typedefs(self):
         """
-        Determines the ctypes data types of the Task and Cal handles 
+        Determines the ctypes data types of the Task and Cal handles
         based on the version of the NI-DAQmx driver installed.
         """
         from nidaqmx.system.system import System

generated/nidaqmx/errors.py

@@ -13,6 +13,28 @@ class Error(Exception):
     pass
 
 
+class DaqNotFoundError(Error):
+    """
+    Error raised when NI-DAQmx driver is not installed.
+    """
+    pass
+
+
+class DaqNotSupportedError(Error):
+    """
+    Error raised when DAQmx is not supported on this platform.
+    """
+    pass
+
+
+class DaqFunctionNotSupportedError(Error):
+    """
+    Error raised when a specific function isn't supported by the installed
+    version of the NI-DAQmx driver.
+    """
+    pass
+
+
 class DaqError(Error):
     """
     Error raised by any DAQmx method.

src/handwritten/_lib.py

@@ -6,19 +6,17 @@
 import threading
 from typing import cast
 
-from nidaqmx.errors import Error
+from nidaqmx.errors import DaqNotFoundError, DaqNotSupportedError, DaqFunctionNotSupportedError
 
 
-class DaqNotFoundError(Error):
-    pass
+_DAQ_NOT_FOUND_MESSAGE = "Could not find an installation of NI-DAQmx. Please ensure that NI-DAQmx " \
+                         "is installed on this machine or contact National Instruments for support."
 
+_DAQ_NOT_SUPPORTED_MESSAGE = "NI-DAQmx Python is not supported on this platform: {0}. Please " \
+                             "direct any questions or feedback to National Instruments."
 
-class DaqFunctionNotSupportedError(Error):
-    pass
-
-
-class InvalidHandleError(Error):
-    pass
+_FUNCTION_NOT_SUPPORTED_MESSAGE = "The NI-DAQmx function \"{0}\" is not supported in this version " \
+                                  "of NI-DAQmx. Visit ni.com/downloads to upgrade."
 
 
 class c_bool32(ctypes.c_uint):
@@ -95,10 +93,7 @@ def __getattr__(self, function):
                         cfunc.arglock = threading.Lock()
             return cfunc
         except AttributeError:
-            raise DaqFunctionNotSupportedError(
-                'The NI-DAQmx function "{}" is not supported in this '
-                'version of NI-DAQmx. Visit ni.com/downloads to upgrade your '
-                'version of NI-DAQmx.'.format(function))
+            raise DaqFunctionNotSupportedError(_FUNCTION_NOT_SUPPORTED_MESSAGE.format(function))
 
 
 class DaqLibImporter:
@@ -147,28 +142,24 @@ def _import_lib(self):
         cdll = None
 
         if sys.platform.startswith('win') or sys.platform.startswith('cli'):
-            if 'iron' in platform.python_implementation().lower():
-                windll = ctypes.windll.nicaiu
-                cdll = ctypes.cdll.nicaiu
-            else:
-                windll = ctypes.windll.LoadLibrary('nicaiu')
-                cdll = ctypes.cdll.LoadLibrary('nicaiu')
-
+            try:
+                if 'iron' in platform.python_implementation().lower():
+                    windll = ctypes.windll.nicaiu
+                    cdll = ctypes.cdll.nicaiu
+                else:
+                    windll = ctypes.windll.LoadLibrary('nicaiu')
+                    cdll = ctypes.cdll.LoadLibrary('nicaiu')
+            except (OSError, WindowsError) as e:
+                raise DaqNotFoundError(_DAQ_NOT_FOUND_MESSAGE) from e
         elif sys.platform.startswith('linux'):
             # On linux you can use the command find_library('nidaqmx')
             if find_library('nidaqmx') is not None:
                 cdll = ctypes.cdll.LoadLibrary(find_library('nidaqmx'))
                 windll = cdll
             else:
-                raise DaqNotFoundError(
-                    'Could not find an installation of NI-DAQmx. Please '
-                    'ensure that NI-DAQmx is installed on this machine or '
-                    'contact National Instruments for support.')
+                raise DaqNotFoundError(_DAQ_NOT_FOUND_MESSAGE)
         else:
-            raise DaqNotFoundError(
-                'NI-DAQmx Python is not supported on this platform: {}. '
-                'Please direct any questions or feedback to National '
-                'Instruments.'.format(sys.platform))
+            raise DaqNotSupportedError(_DAQ_NOT_SUPPORTED_MESSAGE.format(sys.platform))
 
         self._windll = DaqFunctionImporter(windll)
         self._cdll = DaqFunctionImporter(cdll)
@@ -184,7 +175,7 @@ def _get_task_handle_type(driver_version):
 
     def _parse_typedefs(self):
         """
-        Determines the ctypes data types of the Task and Cal handles 
+        Determines the ctypes data types of the Task and Cal handles
         based on the version of the NI-DAQmx driver installed.
         """
         from nidaqmx.system.system import System

src/handwritten/errors.py

@@ -13,6 +13,28 @@ class Error(Exception):
     pass
 
 
+class DaqNotFoundError(Error):
+    """
+    Error raised when NI-DAQmx driver is not installed.
+    """
+    pass
+
+
+class DaqNotSupportedError(Error):
+    """
+    Error raised when DAQmx is not supported on this platform.
+    """
+    pass
+
+
+class DaqFunctionNotSupportedError(Error):
+    """
+    Error raised when a specific function isn't supported by the installed
+    version of the NI-DAQmx driver.
+    """
+    pass
+
+
 class DaqError(Error):
     """
     Error raised by any DAQmx method.