guard missing imports

Author: damccorm

sdks/python/apache_beam/io/requestresponse.py

@@ -35,7 +35,6 @@
 from typing import TypeVar
 from typing import Union
 
-import redis
 from google.api_core.exceptions import TooManyRequests
 
 import apache_beam as beam
@@ -46,6 +45,11 @@
 from apache_beam.transforms.util import BatchElements
 from apache_beam.utils import retry
 
+try:
+  import redis
+except ImportError:
+  redis = None
+
 RequestT = TypeVar('RequestT')
 ResponseT = TypeVar('ResponseT')
 
@@ -689,6 +693,10 @@ def __init__(
     self._kwargs = kwargs if kwargs else {}
     self._source_caller = None
 
+    if redis is None:
+      raise ImportError('Failed to import redis. You can ensure it is '
+                        'installed by installing the redis beam extra')
+
   def get_read(self):
     """get_read returns a PTransform for reading from the cache."""
     ensure_coders_exist(self._request_coder)

sdks/python/tox.ini

@@ -33,7 +33,7 @@ pip_pre = True
 # allow apps that support color to use it.
 passenv=TERM,CLOUDSDK_CONFIG,DOCKER_*,TESTCONTAINERS_*,TC_*,ALLOYDB_PASSWORD
 # Set [] options for pip installation of apache-beam tarball.
-extras = test,dataframe,tfrecord,yaml
+extras = test,dataframe,redis,tfrecord,yaml
 # Don't warn that these commands aren't installed.
 allowlist_externals =
   false