feat: Add support for Zstandard files, closes #1224

Author: jpmckinney

CHANGELOG.rst

@@ -1,6 +1,7 @@
 Unreleased
 ----------
 
+* feat: Add support for Zstandard files with the ``.zst`` extension, if the ``zstandard`` package is installed.
 * feat: :doc:`/scripts/csvformat` adds a :code:`--out-asv` (:code:`--A`) option to use the ASCII unit separator and record separator.
 
 1.4.0 - February 13, 2024

csvkit/cli.py

@@ -17,6 +17,11 @@
 
 from csvkit.exceptions import ColumnIdentifierError, RequiredHeaderError
 
+try:
+    import zstandard
+except ImportError:
+    zstandard = None
+
 
 class LazyFile:
     """
@@ -250,8 +255,10 @@ def _open_input_file(self, path, opened=False):
                 func = gzip.open
             elif extension == '.bz2':
                 func = bz2.open
-            elif extension == ".xz":
+            elif extension == '.xz':
                 func = lzma.open
+            elif extension == '.zst' and zstandard:
+                func = zstandard.open
             else:
                 func = open
 

docs/tutorial/1_getting_started.rst

@@ -22,6 +22,12 @@ Installing csvkit is easy:
 
 If you have problems installing, look for help  in the :doc:`../tricks` section of the documentation.
 
+If you need to work with `Zstandard <https://facebook.github.io/zstd/>`_ files with the ``.zst`` extension, install Zstandard support:
+
+.. code-block:: bash
+
+   sudo pip install csvkit[zstandard]
+
 .. note::
 
    If you're familiar with `virtualenv <https://virtualenv.readthedocs.org/en/latest/>`_, it is better to install csvkit in its own environment. If you are doing this, then you should leave off the ``sudo`` in the previous command.

setup.py

@@ -69,6 +69,9 @@
         'importlib_metadata; python_version < "3.10"',
     ],
     extras_require={
+        'zstandard': [
+            'zstandard',
+        ],
         'test': [
             'coverage>=4.4.2',
             'pytest',