Eliminate GPU build; remove explicit TF dep., replace with checks in …

…__init__.py

PiperOrigin-RevId: 219516463

CONTRIBUTING.md

@@ -46,16 +46,17 @@ To run existing unit-tests on CPU, use the command:
 
 
 ```shell
-bazel test --copt=-O3 --copt=-march=native \
-    //tensorflow_probability/...
+bazel test --copt=-O3 --copt=-march=native //tensorflow_probability/...
 ```
 
 from the root of the `tensorflow_probability` repository. To run tests on GPU,
-use the command:
+you just need to ensure the GPU-enabled version of TensorFlow is installed.
+However, you will also need to include the flag `--jobs=1`, since by default
+Bazel will run many tests in parallel, and each one will try to claim all the
+GPU memory:
 
 ```shell
-bazel test --copt=-O3 --copt=-march=native --config=cuda \
-    //tensorflow_probability/...
+bazel test --jobs=1 --copt=-O3 --copt=-march=native //tensorflow_probability/...
 ```
 
 

README.md

@@ -121,20 +121,15 @@ To install the latest version, run the following:
 pip install --user --upgrade tensorflow-probability  # depends on tensorflow (CPU-only)
 ```
 
-TensorFlow Probability depends on a recent stable release of TensorFlow
-(pip package `tensorflow`); see [TFP release notes](
-https://github.com/tensorflow/probability/releases) for details on the latest
-version of TensorFlow Probability, and the version of TensorFlow it depends on.
+TensorFlow Probability depends on a recent stable release of
+[TensorFlow](https://www.tensorflow.org/install) (pip package `tensorflow`). See
+the [TFP release notes](https://github.com/tensorflow/probability/releases) for
+details about dependencies between TensorFlow and TensorFlow Probability.
 
-We also provide a GPU-enabled package:
-
-```shell
-pip install --user --upgrade tensorflow-probability-gpu  # depends on tensorflow-gpu
-```
-
-Currently, TensorFlow Probability does not contain any GPU-specific code. The
-primary difference between these packages is that `tensorflow-probability-gpu`
-depends on a GPU-enabled version of TensorFlow.
+Note: Since TensorFlow is *not* included as a dependency of the TensorFlow
+Probability package (in `setup.py`), you must explicitly install the TensorFlow
+package (`tensorflow` or `tensorflow-gpu`). This allows us to maintain one
+package instead of separate packages for CPU and GPU-enabled TensorFlow.
 
 To force a Python 3-specific install, replace `pip` with `pip3` in the above
 commands. For additional installation help, guidance installing prerequisites,
@@ -143,10 +138,10 @@ installation guide](https://www.tensorflow.org/install).
 
 ### Nightly Builds
 
-We also release nightly builds, under the pip packages `tfp-nightly` and
-`tfp-nightly-gpu`; these depend on `tf-nightly` and `tf-nightly-gpu`,
-respectively. These builds include newer features, but may be less stable than
-our versioned releases.
+There are also nightly builds of TensorFlow Probability under the pip package
+`tfp-nightly`, which depends on one of `tf-nightly` and `tf-nightly-gpu`.
+Nightly builds include newer features, but may be less stable than the versioned
+releases.
 
 ### Installing from Source
 

setup.py

@@ -33,37 +33,21 @@
     'numpy >= 1.13.3',
 ]
 
-REQUIRED_TENSORFLOW_VERSION = '1.10.0'
-
-if '--gpu' in sys.argv:
-  use_gpu = True
-  sys.argv.remove('--gpu')
-else:
-  use_gpu = False
-
 if '--release' in sys.argv:
   release = True
   sys.argv.remove('--release')
 else:
   # Build a nightly package by default.
   release = False
 
-maybe_gpu_suffix = '-gpu' if use_gpu else ''
-
 if release:
-  project_name = 'tensorflow-probability' + maybe_gpu_suffix
-  tensorflow_package_name = 'tensorflow{}>={}'.format(
-      maybe_gpu_suffix, REQUIRED_TENSORFLOW_VERSION)
+  project_name = 'tensorflow-probability'
 else:
   # Nightly releases use date-based versioning of the form
   # '0.0.1.dev20180305'
-  project_name = 'tfp-nightly' + maybe_gpu_suffix
+  project_name = 'tfp-nightly'
   datestring = datetime.datetime.now().strftime('%Y%m%d')
   __version__ += datestring
-  tensorflow_package_name = 'tf-nightly{}'.format(
-      maybe_gpu_suffix)
-
-REQUIRED_PACKAGES.append(tensorflow_package_name)
 
 
 class BinaryDistribution(Distribution):

tensorflow_probability/__init__.py

@@ -17,6 +17,64 @@
 # Contributors to the `python/` dir should not alter this file; instead update
 # `python/__init__.py` as necessary.
 
+
+# We need to put some imports inside a function call below, and the function
+# call needs to come before the *actual* imports that populate the
+# tensorflow_probability namespace. Hence, we disable this lint check throughout
+# the file.
+#
+# pylint: disable=g-import-not-at-top
+
+
+# Ensure TensorFlow is importable and its version is sufficiently recent. This
+# needs to happen before anything else, since the imports below will try to
+# import tensorflow, too.
+def _ensure_tf_install():  # pylint: disable=g-statement-before-imports
+  """Attempt to import tensorflow, and ensure its version is sufficient.
+
+  Raises:
+    ImportError: if either tensorflow is not importable or its version is
+    inadequate.
+  """
+  try:
+    import tensorflow as tf
+  except ImportError:
+    # Re-raise with more informative error message.
+    raise ImportError(
+        "Failed to import TensorFlow. Please note that TensorFlow is not "
+        "installed by default when you install TensorFlow Probability. This is "
+        "so that users can decide whether to install the GPU-enabled "
+        "TensorFlow package. To use TensorFlow Probability, please install the "
+        "most recent version of TensorFlow, by following instructions at "
+        "https://tensorflow.org/install.")
+
+  import distutils.version
+
+  #
+  # Update this whenever we need to depend on a newer TensorFlow release.
+  #
+  required_tensorflow_version = "1.11.0"
+
+  if (distutils.version.LooseVersion(tf.__version__) <
+      distutils.version.LooseVersion(required_tensorflow_version)):
+    raise ImportError(
+        "This version of TensorFlow Probability requires TensorFlow "
+        "version >= {required}; Detected an installation of version {present}. "
+        "Please upgrade TensorFlow to proceed.".format(
+            required=required_tensorflow_version,
+            present=tf.__version__))
+
+
+_ensure_tf_install()
+
+
+# Cleanup symbols to avoid polluting namespace.
+import sys as _sys
+for symbol in ["_ensure_tf_install", "_sys"]:
+  delattr(_sys.modules[__name__], symbol)
+
+
 # from tensorflow_probability.google import staging  # DisableOnExport
 from tensorflow_probability.python import *  # pylint: disable=wildcard-import
 from tensorflow_probability.python.version import __version__
+# pylint: enable=g-import-not-at-top

tensorflow_probability/g3doc/install.md

@@ -5,24 +5,18 @@
 Install the latest version of TensorFlow Probability:
 
 <pre class="devsite-terminal devsite-click-to-copy prettyprint lang-shell">
-pip install --upgrade tensorflow-probability  # depends on tensorflow (CPU-only)
+pip install --upgrade tensorflow-probability
 </pre>
 
-TensorFlow Probability depends on a recent stable release of TensorFlow
-(pip package `tensorflow`), see the
-[TFP release notes](https://github.com/tensorflow/probability/releases) for
-details about the latest version of TensorFlow Probability and the version of
-TensorFlow it depends on.
+TensorFlow Probability depends on a recent stable release of
+[TensorFlow](https://www.tensorflow.org/install) (pip package `tensorflow`). See
+the [TFP release notes](https://github.com/tensorflow/probability/releases) for
+details about dependencies between TensorFlow and TensorFlow Probability.
 
-There is also a GPU-enabled package:
-
-<pre class="devsite-terminal devsite-click-to-copy prettyprint lang-shell">
-pip install --upgrade tensorflow-probability-gpu  # depends on tensorflow-gpu
-</pre>
-
-Currently, TensorFlow Probability does not contain any GPU-specific code. The
-primary difference between these packages is that `tensorflow-probability-gpu`
-depends on a GPU-enabled version of TensorFlow.
+Note: Since TensorFlow is *not* included as a dependency of the TensorFlow
+Probability package (in `setup.py`), you must explicitly install the TensorFlow
+package (`tensorflow` or `tensorflow-gpu`). This allows us to maintain one
+package instead of separate packages for CPU and GPU-enabled TensorFlow.
 
 To force a Python 3-specific install, replace `pip` with `pip3` in the above
 commands. For additional installation help, guidance installing prerequisites,
@@ -31,10 +25,10 @@ installation guide](https://www.tensorflow.org/install).
 
 ## Nightly builds
 
-There are also nightly builds of TensorFlow Probability under the pip packages
-`tfp-nightly` and `tfp-nightly-gpu`, which depend on `tf-nightly` and
-`tf-nightly-gpu`, respectively. These builds include newer features, but may be
-less stable than the versioned releases.
+There are also nightly builds of TensorFlow Probability under the pip package
+`tfp-nightly`, which depend on one of `tf-nightly` and `tf-nightly-gpu`. Nightly
+builds include newer features, but may be less stable than the versioned
+releases.
 
 ## Install from source