TST: pytest deprecation warnings GH17197

Test parameters with marks are updated according to the updated API of
Pytest.
https://docs.pytest.org/en/latest/changelog.html#pytest-3-2-0-2017-07-30
https://docs.pytest.org/en/latest/parametrize.html

Author: swyoon

doc/source/contributing.rst

@@ -598,6 +598,10 @@ Like many packages, *pandas* uses `pytest
 extensions in `numpy.testing
 <http://docs.scipy.org/doc/numpy/reference/routines.testing.html>`_.
 
+.. note::
+
+   The earliest supported pytest version is 3.1.0.
+
 Writing tests
 ~~~~~~~~~~~~~
 
@@ -709,6 +713,10 @@ A test run of this yields
 
 Tests that we have ``parametrized`` are now accessible via the test name, for example we could run these with ``-k int8`` to sub-select *only* those tests which match ``int8``.
 
+.. note::
+
+   When marking a parameter, ``pytest.param(, marks=...)`` should be used. Otherwise, it will raise ``RemovedInPytest4Warning``.
+   See `pytest documentation <https://docs.pytest.org/en/latest/parametrize.html>`_.
 
 .. code-block:: shell
 

pandas/tests/computation/test_eval.py

@@ -38,13 +38,14 @@
 
 
 @pytest.fixture(params=(
-    pytest.mark.skipif(engine == 'numexpr' and not _USE_NUMEXPR,
-                       reason='numexpr enabled->{enabled}, '
-                              'installed->{installed}'.format(
-                                  enabled=_USE_NUMEXPR,
-                                  installed=_NUMEXPR_INSTALLED))(engine)
-                       for engine in _engines  # noqa
-))
+    pytest.param(engine,
+                 marks=pytest.mark.skipif(
+                     engine == 'numexpr' and not _USE_NUMEXPR,
+                     reason='numexpr enabled->{enabled}, '
+                            'installed->{installed}'.format(
+                                enabled=_USE_NUMEXPR,
+                                installed=_NUMEXPR_INSTALLED)))
+                 for engine in _engines))  # noqa
 def engine(request):
     return request.param
 

pandas/tests/io/parser/test_network.py

@@ -23,8 +23,10 @@ def salaries_table():
 @pytest.mark.parametrize(
     "compression,extension",
     [('gzip', '.gz'), ('bz2', '.bz2'), ('zip', '.zip'),
-     pytest.mark.skipif(not tm._check_if_lzma(),
-                        reason='need backports.lzma to run')(('xz', '.xz'))])
+     pytest.param('xz', '.xz',
+                  marks=pytest.mark.skipif(not tm._check_if_lzma(),
+                                           reason='need backports.lzma '
+                                                  'to run'))])
 @pytest.mark.parametrize('mode', ['explicit', 'infer'])
 @pytest.mark.parametrize('engine', ['python', 'c'])
 def test_compressed_urls(salaries_table, compression, extension, mode, engine):

pandas/tests/io/test_excel.py

@@ -2400,8 +2400,10 @@ def check_called(func):
 
 
 @pytest.mark.parametrize('engine', [
-    pytest.mark.xfail('xlwt', reason='xlwt does not support '
-                                     'openpyxl-compatible style dicts'),
+    pytest.param('xlwt',
+                 marks=pytest.mark.xfail(reason='xlwt does not support '
+                                                'openpyxl-compatible '
+                                                'style dicts')),
     'xlsxwriter',
     'openpyxl',
 ])

pandas/tests/io/test_parquet.py

@@ -26,10 +26,14 @@
 
 # setup engines & skips
 @pytest.fixture(params=[
-    pytest.mark.skipif(not _HAVE_FASTPARQUET,
-                       reason='fastparquet is not installed')('fastparquet'),
-    pytest.mark.skipif(not _HAVE_PYARROW,
-                       reason='pyarrow is not installed')('pyarrow')])
+    pytest.param('fastparquet',
+                 marks=pytest.mark.skipif(not _HAVE_FASTPARQUET,
+                                          reason='fastparquet is '
+                                                 'not installed')),
+    pytest.param('pyarrow',
+                 marks=pytest.mark.skipif(not _HAVE_PYARROW,
+                                          reason='pyarrow is '
+                                                 'not installed'))])
 def engine(request):
     return request.param
 

pandas/tests/test_window.py

@@ -530,8 +530,9 @@ def test_numpy_compat(self):
 
     @pytest.mark.parametrize(
         'expander',
-        [1, pytest.mark.xfail(
-            reason='GH 16425 expanding with offset not supported')('1s')])
+        [1, pytest.param('ls', marks=pytest.mark.xfail(
+                         reason='GH 16425 expanding with '
+                                'offset not supported'))])
     def test_empty_df_expanding(self, expander):
         # GH 15819 Verifies that datetime and integer expanding windows can be
         # applied to empty DataFrames