TST: Streaming of S3 files (pandas-dev#22520)

Author: kokes

pandas/tests/io/test_s3.py

@@ -1,3 +1,7 @@
+import pytest
+
+from pandas import read_csv
+from pandas.compat import BytesIO
 from pandas.io.common import is_s3_url
 
 
@@ -6,3 +10,18 @@ class TestS3URL(object):
     def test_is_s3_url(self):
         assert is_s3_url("s3://pandas/somethingelse.com")
         assert not is_s3_url("s4://pandas/somethingelse.com")
+
+
+def test_streaming_s3_objects():
+    # GH17135
+    # botocore gained iteration support in 1.10.47, can now be used in read_*
+    pytest.importorskip('botocore', minversion='1.10.47')
+    from botocore.response import StreamingBody
+
+    data = [
+        b'foo,bar,baz\n1,2,3\n4,5,6\n',
+        b'just,the,header\n',
+    ]
+    for el in data:
+        body = StreamingBody(BytesIO(el), content_length=len(el))
+        read_csv(body)