TST: Clean up json/test_compression.py (pandas-dev#19331)

Author: reidy-p

pandas/tests/io/json/test_compression.py

@@ -1,38 +1,10 @@
 import pytest
 
 import pandas as pd
-from pandas import compat
 import pandas.util.testing as tm
-import pandas.util._test_decorators as td
 from pandas.util.testing import assert_frame_equal, assert_raises_regex
 
 
-COMPRESSION_TYPES = [None, 'bz2', 'gzip',
-                     pytest.param('xz', marks=td.skip_if_no_lzma)]
-
-
-def decompress_file(path, compression):
-    if compression is None:
-        f = open(path, 'rb')
-    elif compression == 'gzip':
-        import gzip
-        f = gzip.GzipFile(path, 'rb')
-    elif compression == 'bz2':
-        import bz2
-        f = bz2.BZ2File(path, 'rb')
-    elif compression == 'xz':
-        lzma = compat.import_lzma()
-        f = lzma.open(path, 'rb')
-    else:
-        msg = 'Unrecognized compression type: {}'.format(compression)
-        raise ValueError(msg)
-
-    result = f.read().decode('utf8')
-    f.close()
-    return result
-
-
-@pytest.mark.parametrize('compression', COMPRESSION_TYPES)
 def test_compression_roundtrip(compression):
     df = pd.DataFrame([[0.123456, 0.234567, 0.567567],
                        [12.32112, 123123.2, 321321.2]],
@@ -43,8 +15,9 @@ def test_compression_roundtrip(compression):
         assert_frame_equal(df, pd.read_json(path, compression=compression))
 
         # explicitly ensure file was compressed.
-        uncompressed_content = decompress_file(path, compression)
-        assert_frame_equal(df, pd.read_json(uncompressed_content))
+        with tm.decompress_file(path, compression) as fh:
+            result = fh.read().decode('utf8')
+        assert_frame_equal(df, pd.read_json(result))
 
 
 def test_compress_zip_value_error():
@@ -67,7 +40,6 @@ def test_read_zipped_json():
     assert_frame_equal(uncompressed_df, compressed_df)
 
 
-@pytest.mark.parametrize('compression', COMPRESSION_TYPES)
 def test_with_s3_url(compression):
     boto3 = pytest.importorskip('boto3')
     pytest.importorskip('s3fs')
@@ -88,7 +60,6 @@ def test_with_s3_url(compression):
         assert_frame_equal(df, roundtripped_df)
 
 
-@pytest.mark.parametrize('compression', COMPRESSION_TYPES)
 def test_lines_with_compression(compression):
     with tm.ensure_clean() as path:
         df = pd.read_json('{"a": [1, 2, 3], "b": [4, 5, 6]}')
@@ -98,7 +69,6 @@ def test_lines_with_compression(compression):
         assert_frame_equal(df, roundtripped_df)
 
 
-@pytest.mark.parametrize('compression', COMPRESSION_TYPES)
 def test_chunksize_with_compression(compression):
     with tm.ensure_clean() as path:
         df = pd.read_json('{"a": ["foo", "bar", "baz"], "b": [4, 5, 6]}')