Linter seems unhappy with conditional imports. Make gfile a module-level import.

I usually do this as a conditional because tf takes a while to load and it's nice to skip it when you want to run a script that just preps data or something like that, but it doesn't seem like a big deal.

training/deepspeech_training/util/io.py

@@ -3,9 +3,8 @@ A set of I/O utils that allow us to open files on remote storage as if they were
 into HDFS storage using Tensorflow's C++ FileStream API.
 Currently only includes wrappers for Google's GCS, but this can easily be expanded for AWS S3 buckets.
 """
-import inspect
 import os
-import sys
+from tensorflow.io import gfile
 
 
 def is_remote_path(path):
@@ -21,9 +20,7 @@ def path_exists_remote(path):
     Wrapper that allows existance check of local and remote paths like
     `gs://...`
     """
-    # Conditional import
     if is_remote_path(path):
-        from tensorflow.io import gfile
         return gfile.exists(path)
     return os.path.exists(path)
 
@@ -32,7 +29,6 @@ def copy_remote(src, dst, overwrite=False):
     """
     Allows us to copy a file from local to remote or vice versa
     """
-    from tensorflow.io import gfile
     return gfile.copy(src, dst, overwrite)
 
 
@@ -47,9 +43,7 @@ def open_remote(path, mode='r', buffering=-1, encoding=None, newline=None, close
     with open_remote('gs://.....', mode='w+') as f:
         do something with the file f, whether or not we have local access to it
     """
-    # Conditional import
     if is_remote_path(path):
-        from tensorflow.io import gfile
         return gfile.GFile(path, mode=mode)
     return open(path, mode, buffering=buffering, encoding=encoding, newline=newline, closefd=closefd, opener=opener)
 
@@ -58,9 +52,7 @@ def isdir_remote(path):
     """
     Wrapper to check if remote and local paths are directories
     """
-    # Conditional import
     if is_remote_path(path):
-        from tensorflow.io import gfile
         return gfile.isdir(path)
     return os.path.isdir(path)
 
@@ -69,9 +61,7 @@ def listdir_remote(path):
     """
     Wrapper to list paths in local dirs (alternative to using a glob, I suppose)
     """
-    # Conditional import
     if is_remote_path(path):
-        from tensorflow.io import gfile
         return gfile.listdir(path)
     return os.listdir(path)
 
@@ -80,9 +70,6 @@ def glob_remote(filename):
     """
     Wrapper that provides globs on local and remote paths like `gs://...`
     """
-    # Conditional import
-    from tensorflow.io import gfile
-
     return gfile.glob(filename)
 
 
@@ -91,6 +78,4 @@ def remove_remote(filename):
     Wrapper that can remove_remote local and remote files like `gs://...`
     """
     # Conditional import
-    from tensorflow.io import gfile
-
     return gfile.remove_remote(filename)