fix for minimal pkg not throw (#3199)

* fix import check not throw

* python2 import error __str__ uses args instead of message

* tuple forwarding

src/python/turicreate/_deps/minimal_package.py

@@ -74,12 +74,26 @@ def _minimal_package_import_check(name):
             else:
                 version = __version__
 
-            # append more information
-            e.msg = (
-                "{}. This is a minimal package for SFrame only, without {} pinned"
+            # append more information from Import error
+            emsg = str(e)
+            emsg = (
+                "{}.\nThis is a minimal package for SFrame only, without {} pinned"
                 " as a dependency. You can try install all required packages by installing"
                 " the full package. For example:\n"
                 "pip install --force-reinstall turicreate=={}\n"
-            ).format(e.msg, name, version)
+            ).format(emsg, name, version)
+
+            if six.PY2:
+                # __str__ and __repr__ uses `args`.
+                # only change the first element of args tuple
+                args = list(e.args)
+                if args:
+                    args[0] = emsg
+                else:
+                    args = (emsg,)
+                e.args = tuple(args)
+                e.message = emsg
+            else:
+                e.msg = emsg
 
         raise e

src/python/turicreate/test/test_minimal_pkg.py

@@ -0,0 +1,26 @@
+# -*- coding: utf-8 -*-
+# Copyright © 2020 Apple Inc. All rights reserved.
+#
+# Use of this source code is governed by a BSD-3-clause license that can
+# be found in the LICENSE.txt file or at https://opensource.org/licenses/BSD-3-Clause
+#
+from __future__ import print_function as _  # noqa
+from __future__ import division as _  # noqa
+from __future__ import absolute_import as _  # noqa
+import turicreate as _tc
+import pytest
+
+pytestmark = [pytest.mark.minimal]
+
+
+@pytest.mark.skipif(not _tc._deps.is_minimal_pkg(), reason="skip when testing full pkg")
+class TestMinimalPackage(object):
+    """ test minimal package for toolkits.
+    well, other toolkits are too hard to setup
+    """
+
+    def test_audio_classifier(self):
+        with pytest.raises(
+            ImportError, match=r".*pip install --force-reinstall turicreate==.*"
+        ):
+            _tc.load_audio("./dummy/audio")

src/python/turicreate/toolkits/audio_analysis/audio_analysis.py

@@ -16,6 +16,7 @@
 
 import turicreate as _tc
 from turicreate.toolkits._main import ToolkitError as _ToolkitError
+from turicreate._deps.minimal_package import _minimal_package_import_check
 
 
 def load_audio(
@@ -60,7 +61,7 @@ def load_audio(
     >>> audio_path = "~/Documents/myAudioFiles/"
     >>> audio_sframe = tc.audio_analysis.load_audio(audio_path, recursive=True)
     """
-    from scipy.io import wavfile as _wavfile
+    _scipy = _minimal_package_import_check("scipy")
 
     path = _tc.util._make_internal_url(path)
 
@@ -84,7 +85,7 @@ def load_audio(
     )
     for cur_file_path in all_wav_files:
         try:
-            sample_rate, data = _wavfile.read(cur_file_path)
+            sample_rate, data = _scipy.io.wavfile.read(cur_file_path)
         except Exception as e:
             error_string = "Could not read {}: {}".format(cur_file_path, e)
             if not ignore_failure:

src/python/turicreate/toolkits/sound_classifier/_audio_feature_extractor.py

@@ -1,8 +1,5 @@
 import time as _time
-
-from coremltools.models import MLModel
 import numpy as _np
-from tensorflow import keras as _keras
 
 # Suppresses verbosity to only errors
 import turicreate.toolkits._tf_utils as _utils
@@ -90,11 +87,13 @@ def __init__(self):
             self.gpu_policy.start()
 
             model_path = vggish_model_file.get_model_path(format="tensorflow")
-            self.vggish_model = _keras.models.load_model(model_path)
+            _tf = _minimal_package_import_check("tensorflow")
+            self.vggish_model = _tf.keras.models.load_model(model_path)
         else:
             # Use Core ML
             model_path = vggish_model_file.get_model_path(format="coreml")
-            self.vggish_model = MLModel(model_path)
+            coremltools = _minimal_package_import_check("coremltools")
+            self.vggish_model = coremltools.models.MLModel(model_path)
 
     def __del__(self):
         if self.mac_ver < (10, 14):
@@ -197,4 +196,5 @@ def get_spec(self):
         else:
             vggish_model_file = VGGish()
             coreml_model_path = vggish_model_file.get_model_path(format="coreml")
-            return MLModel(coreml_model_path).get_spec()
+            coremltools = _minimal_package_import_check("coremltools")
+            return coremltools.models.MLModel(coreml_model_path).get_spec()