veselosky · August 29, 2024 11:32 · Dec 1, 2015 · Dec 1, 2015
diff --git a/s3gzip.py b/s3gzip.py
@@ -45,7 +45,8 @@
 )
 retr = s3.get_object(Bucket=bucket, Key='gztest.txt')
 # Now the fun part. Reading it back requires this little dance, because
-# GzipFile insists that it's underlying file-like thing implement tell and
+# GzipFile insists that its underlying file-like thing implement tell and
 # seek, but boto3's io stream does not.
 bytestream = BytesIO(retr['Body'].read())
 got_text = GzipFile(None, 'rb', fileobj=bytestream).read().decode('utf-8')
+assert got_text == text_body
diff --git a/s3gzip.py b/s3gzip.py
@@ -0,0 +1,51 @@
+# vim: set fileencoding=utf-8 :
+#
+# How to store and retrieve gzip-compressed objects in AWS S3
+###########################################################################
+#
+#   Copyright 2015 Vince Veselosky and contributors
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+from __future__ import absolute_import, print_function, unicode_literals
+from io import BytesIO
+from gzip import GzipFile
+
+import boto3
+s3 = boto3.client('s3')
+bucket = 'bluebucket.mindvessel.net'
+
+# Read in some example text, as unicode
+with open("utext.txt") as fi:
+    text_body = fi.read().decode("utf-8")
+
+# A GzipFile must wrap a real file or a file-like object. We do not want to
+# write to disk, so we use a BytesIO as a buffer.
+gz_body = BytesIO()
+gz = GzipFile(None, 'wb', 9, gz_body)
+gz.write(text_body.encode('utf-8'))  # convert unicode strings to bytes!
+gz.close()
+# GzipFile has written the compressed bytes into our gz_body
+s3.put_object(
+    Bucket=bucket,
+    Key='gztest.txt',  # Note: NO .gz extension!
+    ContentType='text/plain',  # the original type
+    ContentEncoding='gzip',  # MUST have or browsers will error
+    Body=gz_body.getvalue()
+)
+retr = s3.get_object(Bucket=bucket, Key='gztest.txt')
+# Now the fun part. Reading it back requires this little dance, because
+# GzipFile insists that it's underlying file-like thing implement tell and
+# seek, but boto3's io stream does not.
+bytestream = BytesIO(retr['Body'].read())
+got_text = GzipFile(None, 'rb', fileobj=bytestream).read().decode('utf-8')