Issue #3488: Provide convenient shorthand functions gzip.compress

and `gzip.decompress`.  Original patch by Anand B. Pillai.

Lib/gzip.py

@@ -10,7 +10,7 @@ import zlib
 import builtins
 import io
 
-__all__ = ["GzipFile","open"]
+__all__ = ["GzipFile", "open", "compress", "decompress"]
 
 FTEXT, FHCRC, FEXTRA, FNAME, FCOMMENT = 1, 2, 4, 8, 16
 
@@ -476,6 +476,23 @@ class GzipFile(io.BufferedIOBase):
         return b''.join(bufs) # Return resulting line
 
 
+def compress(data, compresslevel=9):
+    """Compress data in one shot and return the compressed string.
+    Optional argument is the compression level, in range of 1-9.
+    """
+    buf = io.BytesIO()
+    with GzipFile(fileobj=buf, mode='wb', compresslevel=compresslevel) as f:
+        f.write(data)
+    return buf.getvalue()
+
+def decompress(data):
+    """Decompress a gzip compressed string in one shot.
+    Return the decompressed string.
+    """
+    with GzipFile(fileobj=io.BytesIO(data)) as f:
+        return f.read()
+
+
 def _test():
     # Act like gzip; with -d, act like gunzip.
     # The input file is not deleted, however, nor are any other gzip