Use compression.zstd (PEP-784)

Author: Rogdham

pyproject.toml

@@ -39,7 +39,7 @@ azure = ["azure-storage-blob", "azure-common", "azure-core"]
 http = ["requests"]
 webhdfs = ["requests"]
 ssh = ["paramiko"]
-zst = ["zstandard"]
+zst = ["backports.zstd>=1.0.0;python_version<'3.14'"]
 all = ["smart_open[s3,gcs,azure,http,webhdfs,ssh,zst]"]
 test = [
   "smart_open[all]",

smart_open/compression.py

@@ -119,8 +119,12 @@ def _handle_gzip(file_obj, mode):
 
 
 def _handle_zstd(file_obj, mode):
-    import zstandard
-    result = zstandard.open(filename=file_obj, mode=mode)
+    import sys
+    if sys.version_info >= (3, 14):
+        from compression import zstd
+    else:
+        from backports import zstd
+    result = zstd.open(file_obj, mode=mode)
     return _maybe_wrap_buffered(result, mode)
 
 

tests/test_compression.py

@@ -9,9 +9,14 @@
 import gzip
 import io
 import lzma
+import sys
 
 import pytest
-import zstandard as zstd
+
+if sys.version_info >= (3, 14):
+    from compression import zstd
+else:
+    from backports import zstd
 
 import smart_open.compression
 
@@ -35,10 +40,10 @@ def label(thing, name):
         (io.BytesIO(gzip.compress(plain)), 'infer_from_extension', 'file.GZ'),
         (label(io.BytesIO(gzip.compress(plain)), 'file.gz'), 'infer_from_extension', ''),
         (io.BytesIO(gzip.compress(plain)), '.gz', 'file.gz'),
-        (io.BytesIO(zstd.ZstdCompressor().compress(plain)), 'infer_from_extension', 'file.zst'),
-        (io.BytesIO(zstd.ZstdCompressor().compress(plain)), 'infer_from_extension', 'file.ZST'),
-        (label(io.BytesIO(zstd.ZstdCompressor().compress(plain)), 'file.zst'), 'infer_from_extension', ''),
-        (io.BytesIO(zstd.ZstdCompressor().compress(plain)), '.zst', 'file.zst'),
+        (io.BytesIO(zstd.compress(plain)), 'infer_from_extension', 'file.zst'),
+        (io.BytesIO(zstd.compress(plain)), 'infer_from_extension', 'file.ZST'),
+        (label(io.BytesIO(zstd.compress(plain)), 'file.zst'), 'infer_from_extension', ''),
+        (io.BytesIO(zstd.compress(plain)), '.zst', 'file.zst'),
         (io.BytesIO(lzma.compress(plain)), 'infer_from_extension', 'file.xz'),
         (io.BytesIO(lzma.compress(plain)), 'infer_from_extension', 'file.XZ'),
         (label(io.BytesIO(lzma.compress(plain)), 'file.xz'), 'infer_from_extension', ''),