title: unable to import pytorch-lightning
body: <p>I installed pytorch-lightning using pip, and I'm running on Mac.
  I tried:</p>
  <pre><code>! pip install pytorch-lightning --upgrade
  ! pip install pytorch-lightning-bolts
  </code></pre>
  <p>(finished successfully)
  and then:</p>
  <pre><code>import pytorch_lightning as pl
  </code></pre>
  <p>and what I get is:</p>
  <p>--</p>
  <pre><code>-------------------------------------------------------------------------
  ImportError                               Traceback (most recent call last)
  &lt;ipython-input-3-f3b4217dcea1&gt; in &lt;module&gt;
        7 from torchvision.datasets import MNIST
        8 from torchvision import transforms
  ----&gt; 9 import pytorch_lightning as pl
       10 from pytorch_lightning.metrics.functional import accuracy
       11 tmpdir = os.getcwd()
  
  /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pytorch_lightning/__init__.py in &lt;module&gt;
       60     # We are not importing the rest of the lightning during the build process, as it may not be compiled yet
       61 else:
  ---&gt; 62     from pytorch_lightning import metrics
       63     from pytorch_lightning.callbacks import Callback
       64     from pytorch_lightning.core import LightningDataModule, LightningModule
  
  /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pytorch_lightning/metrics/__init__.py in &lt;module&gt;
       12 # See the License for the specific language governing permissions and
       13 # limitations under the License.
  ---&gt; 14 from pytorch_lightning.metrics.classification import (  # noqa: F401
       15     Accuracy,
       16     AUC,
  
  /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pytorch_lightning/metrics/classification/__init__.py in &lt;module&gt;
       12 # See the License for the specific language governing permissions and
       13 # limitations under the License.
  ---&gt; 14 from pytorch_lightning.metrics.classification.accuracy import Accuracy  # noqa: F401
       15 from pytorch_lightning.metrics.classification.auc import AUC  # noqa: F401
       16 from pytorch_lightning.metrics.classification.auroc import AUROC  # noqa: F401
  
  /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pytorch_lightning/metrics/classification/accuracy.py in &lt;module&gt;
       16 import torch
       17 
  ---&gt; 18 from pytorch_lightning.metrics.functional.accuracy import _accuracy_compute, _accuracy_update
       19 from pytorch_lightning.metrics.metric import Metric
       20 
  
  /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pytorch_lightning/metrics/functional/__init__.py in &lt;module&gt;
       12 # See the License for the specific language governing permissions and
       13 # limitations under the License.
  ---&gt; 14 from pytorch_lightning.metrics.functional.accuracy import accuracy  # noqa: F401
       15 from pytorch_lightning.metrics.functional.auc import auc  # noqa: F401
       16 from pytorch_lightning.metrics.functional.auroc import auroc  # noqa: F401
  
  /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pytorch_lightning/metrics/functional/accuracy.py in &lt;module&gt;
       16 import torch
       17 
  ---&gt; 18 from pytorch_lightning.metrics.classification.helpers import _input_format_classification, DataType
       19 
       20 
  
  /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pytorch_lightning/metrics/classification/helpers.py in &lt;module&gt;
       17 import torch
       18 
  ---&gt; 19 from pytorch_lightning.metrics.utils import select_topk, to_onehot
       20 from pytorch_lightning.utilities import LightningEnum
       21 
  
  /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pytorch_lightning/metrics/utils.py in &lt;module&gt;
       16 import torch
       17 
  ---&gt; 18 from pytorch_lightning.utilities import rank_zero_warn
       19 
       20 METRIC_EPS = 1e-6
  
  /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pytorch_lightning/utilities/__init__.py in &lt;module&gt;
       16 import numpy
       17 
  ---&gt; 18 from pytorch_lightning.utilities.apply_func import move_data_to_device  # noqa: F401
       19 from pytorch_lightning.utilities.distributed import (  # noqa: F401
       20     AllGatherGrad,
  
  /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pytorch_lightning/utilities/apply_func.py in &lt;module&gt;
       23 
       24 from pytorch_lightning.utilities.exceptions import MisconfigurationException
  ---&gt; 25 from pytorch_lightning.utilities.imports import _TORCHTEXT_AVAILABLE
       26 
       27 if _TORCHTEXT_AVAILABLE:
  
  /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pytorch_lightning/utilities/imports.py in &lt;module&gt;
       54 _TORCH_GREATER_EQUAL_1_7 = _compare_version(&quot;torch&quot;, operator.ge, &quot;1.7.0&quot;)
       55 _TORCH_QUANTIZE_AVAILABLE = bool([eg for eg in torch.backends.quantized.supported_engines if eg != 'none'])
  ---&gt; 56 _APEX_AVAILABLE = _module_available(&quot;apex.amp&quot;)
       57 _BOLTS_AVAILABLE = _module_available('pl_bolts')
       58 _DEEPSPEED_AVAILABLE = not _IS_WINDOWS and _module_available('deepspeed')
  
  /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pytorch_lightning/utilities/imports.py in _module_available(module_path)
       32     &quot;&quot;&quot;
       33     try:
  ---&gt; 34         return find_spec(module_path) is not None
       35     except AttributeError:
       36         # Python 3.6
  
  /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/importlib/util.py in find_spec(name, package)
       92         parent_name = fullname.rpartition('.')[0]
       93         if parent_name:
  ---&gt; 94             parent = __import__(parent_name, fromlist=['__path__'])
       95             try:
       96                 parent_path = parent.__path__
  
  /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/apex/__init__.py in &lt;module&gt;
       11                                 ISessionFactory)
       12 from pyramid.security import NO_PERMISSION_REQUIRED
  ---&gt; 13 from pyramid.session import UnencryptedCookieSessionFactoryConfig
       14 from pyramid.settings import asbool
       15 
  
  ImportError: cannot import name 'UnencryptedCookieSessionFactoryConfig' from 'pyramid.session' (unknown location
  </code></pre>