Suppress CoreML converter warnings on import

Resolves #536.

kraken/lib/layers.py

@@ -2,13 +2,18 @@
 Layers for VGSL models
 """
 import torch
+import logging
 import numpy as np
 
 from typing import List, Tuple, Optional, Iterable
 from torch.nn import Module, Sequential
 from torch.nn import functional as F
 from torch.nn.utils.rnn import pad_packed_sequence, pack_padded_sequence
+
+logger = logging.getLogger('coremltools')
+logger.setLevel(logging.ERROR)
 from coremltools.proto import NeuralNetwork_pb2
+logger.setLevel(logging.WARNING)
 
 # all tensors are ordered NCHW, the "feature" dimension is C, so the output of
 # an LSTM will be put into C same as the filters of a CNN.

kraken/lib/vgsl.py

@@ -15,14 +15,9 @@
 from kraken.lib.codec import PytorchCodec
 from kraken.lib.exceptions import KrakenInvalidModelException
 
-# filter out coreml warnings coming from their conversion routines (which we don't use).
-with warnings.catch_warnings():
-    warnings.filterwarnings(action='ignore', message='has not been tested with coremltools')
-    warnings.filterwarnings(action='ignore', message='is not supported')
-
-    from coremltools.models import MLModel
-    from coremltools.models import datatypes
-    from coremltools.models.neural_network import NeuralNetworkBuilder
+from coremltools.models import MLModel
+from coremltools.models import datatypes
+from coremltools.models.neural_network import NeuralNetworkBuilder
 
 from google.protobuf.message import DecodeError