Move Keras as an optional dependency (#319)

Fixes #317

.isort.cfg

@@ -4,4 +4,4 @@ include_trailing_comma=True
 force_grid_wrap=0
 use_parentheses=True
 line_length=88
-known_third_party = dateutil,flask,hglib,imblearn,jsone,keras,libmozdata,numpy,pandas,parsepatch,pytest,requests,setuptools,shap,sklearn,taskcluster,tqdm,xgboost,yaml,zstandard
+known_third_party = dateutil,flask,hglib,imblearn,jsone,libmozdata,numpy,pandas,parsepatch,pytest,requests,setuptools,shap,sklearn,taskcluster,tqdm,xgboost,yaml,zstandard

MANIFEST.in

@@ -1,6 +1,7 @@
 include VERSION
 include requirements.txt
 include extra-nlp-requirements.txt
+include extra-nn-requirements.txt
 recursive-include bugbug/labels *
 
 recursive-exclude * __pycache__

bugbug/models/component_nn.py

@@ -3,18 +3,6 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this file,
 # You can obtain one at http://mozilla.org/MPL/2.0/.
 
-from keras import Input, layers
-from keras.layers import (
-    GRU,
-    Bidirectional,
-    Dense,
-    Dropout,
-    Embedding,
-    Flatten,
-    GlobalMaxPooling1D,
-    SpatialDropout1D,
-)
-from keras.models import Model as KerasModel
 from sklearn.ensemble import VotingClassifier
 from sklearn.feature_extraction.text import TfidfVectorizer
 from sklearn.pipeline import Pipeline, make_pipeline
@@ -29,10 +17,29 @@ from bugbug.utils import (
     StructuredColumnTransformer,
 )
 
+OPT_MSG_MISSING = (
+    "Optional dependencies are missing, install them with: pip install bugbug[nn]\n"
+)
+
+try:
+    from keras import Input, layers
+    from keras.layers import (
+        GRU,
+        Bidirectional,
+        Dense,
+        Dropout,
+        Embedding,
+        Flatten,
+        GlobalMaxPooling1D,
+        SpatialDropout1D,
+    )
+    from keras.models import Model as KerasModel
+except ImportError:
+    raise ImportError(OPT_MSG_MISSING)
+
 
 class ComponentNNClassifier(KerasClassifier):
     def __init__(self, **kwargs):
-
         # (epochs, batch_size) combinations
         fit_params = [(2, 256), (2, 512), (1, 1024)]
         super().__init__(fit_params=fit_params)

bugbug/nn.py

@@ -3,13 +3,23 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this file,
 # You can obtain one at http://mozilla.org/MPL/2.0/.
 
-from keras.preprocessing.sequence import pad_sequences
-from keras.preprocessing.text import Tokenizer
-from keras.utils import to_categorical
 from sklearn.base import BaseEstimator, ClassifierMixin, TransformerMixin
 
 from bugbug.utils import numpy_to_dict
 
+OPT_MSG_MISSING = (
+    "Optional dependencies are missing, install them with: pip install bugbug[nn]\n"
+)
+
+try:
+    from keras.preprocessing.sequence import pad_sequences
+    from keras.preprocessing.text import Tokenizer
+    from keras.utils import to_categorical
+
+    HAS_OPTIONAL_DEPENDENCIES = True
+except ImportError:
+    raise ImportError(OPT_MSG_MISSING)
+
 
 class KerasTextToSequences(BaseEstimator, TransformerMixin):
     def __init__(self, maxlen, vocab_size):

extra-nn-requirements.txt

@@ -0,0 +1 @@
+keras==2.2.4

requirements.txt

@@ -10,7 +10,6 @@ python-hglib==2.6.1
 shap==0.28.5
 pandas==0.24.2
 parsepatch==0.1.3
-keras==2.2.4
 tqdm==4.31.1
 python-dateutil==2.8.0
 zstandard==0.11.0

setup.py

@@ -38,7 +38,7 @@ with open(os.path.join(here, "VERSION")) as f:
     version = f.read().strip()
 
 # Read the extra requirements
-extras = ["nlp"]
+extras = ["nlp", "nn"]
 
 extras_require = {}