Remove tensorflow as dependency (#860)

* Removed tensorflow as a dependency.

* Moved the check in a function.

* Added packaging as a dependency.

* Formatted the message better.

* Install tensorflow in the CI.

* Fixed the version number in the CI

* Update setup.py

* Update .travis.yml

Co-authored-by: Haifeng Jin <[email protected]>

autokeras/__init__.py

@@ -35,3 +35,6 @@
 from autokeras.task import StructuredDataRegressor
 from autokeras.task import TextClassifier
 from autokeras.task import TextRegressor
+
+from .utils import check_tf_version
+check_tf_version()

autokeras/utils.py

@@ -1,5 +1,6 @@
 import pickle
 import re
+from packaging.version import parse
 
 import numpy as np
 import tensorflow as tf
@@ -127,3 +128,16 @@ def to_type_key(dictionary, convert_func):
     """
     return {convert_func(key): value
             for key, value in dictionary.items()}
+
+
+def check_tf_version():
+    if parse(tf.__version__) < parse('2.0.0'):
+        raise ImportError(
+            f'The Tensorflow package version needs to be at least v2.0.0 \n'
+            f'for AutoKeras to run. Currently, your TensorFlow version is \n'
+            f'v{tf.__version__}. Please upgrade with \n'
+            f'`$ pip install --upgrade tensorflow` -> GPU version \n'
+            f'or \n'
+            f'`$ pip install --upgrade tensorflow-cpu` -> CPU version. \n'
+            f'You can use `pip freeze` to check afterwards that everything is ok.'
+        )

setup.py

@@ -18,8 +18,9 @@
     url='http://autokeras.com',
     download_url='https://github.com/keras-team/autokeras/archive/1.0.0b0.tar.gz',
     keywords=['AutoML', 'keras'],
+    # TODO: Do not install tensorflow if tensorflow-gpu is installed.
     install_requires=[
-        'tensorflow>=2.0.0',
+        'packaging',
         'keras-tuner>=1.0.0',
         'scikit-learn',
         'numpy',