diff --git a/tests/conftest.py b/tests/conftest.py
index 95a8a47..0b63a0e 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -9,7 +9,7 @@ import os
 import pytest
 
 
-@pytest.fixture(scope='session')
+@pytest.fixture(scope="session")
 def testdata_dir():
     """Path to the testdata directory."""
-    return os.path.join(os.path.dirname(__file__), 'testdata')
+    return os.path.join(os.path.dirname(__file__), "testdata")
diff --git a/tests/test_Arbin.py b/tests/test_Arbin.py
index 2286b2d..d708d3f 100644
--- a/tests/test_Arbin.py
+++ b/tests/test_Arbin.py
@@ -13,8 +13,7 @@ import pytest
 from galvani import res2sqlite
 
 
-have_mdbtools = (subprocess.call(['which', 'mdb-export'],
-                                 stdout=subprocess.DEVNULL) == 0)
+have_mdbtools = subprocess.call(["which", "mdb-export"], stdout=subprocess.DEVNULL) == 0
 
 
 def test_res2sqlite_help():
@@ -22,39 +21,47 @@ def test_res2sqlite_help():
 
     This should work even when mdbtools is not installed.
     """
-    help_output = subprocess.check_output(['res2sqlite', '--help'])
-    assert b'Convert Arbin .res files to sqlite3 databases' in help_output
+    help_output = subprocess.check_output(["res2sqlite", "--help"])
+    assert b"Convert Arbin .res files to sqlite3 databases" in help_output
 
 
-@pytest.mark.skipif(have_mdbtools, reason='This tests the failure when mdbtools is not installed')
+@pytest.mark.skipif(
+    have_mdbtools, reason="This tests the failure when mdbtools is not installed"
+)
 def test_convert_Arbin_no_mdbtools(testdata_dir, tmpdir):
     """Checks that the conversion fails with an appropriate error message."""
-    res_file = os.path.join(testdata_dir, 'arbin1.res')
-    sqlite_file = os.path.join(str(tmpdir), 'arbin1.s3db')
-    with pytest.raises(RuntimeError, match="Could not locate the `mdb-export` executable."):
+    res_file = os.path.join(testdata_dir, "arbin1.res")
+    sqlite_file = os.path.join(str(tmpdir), "arbin1.s3db")
+    with pytest.raises(
+        RuntimeError, match="Could not locate the `mdb-export` executable."
+    ):
         res2sqlite.convert_arbin_to_sqlite(res_file, sqlite_file)
 
 
-@pytest.mark.skipif(not have_mdbtools, reason='Reading the Arbin file requires MDBTools')
-@pytest.mark.parametrize('basename', ['arbin1', 'UM34_Test005E'])
+@pytest.mark.skipif(
+    not have_mdbtools, reason="Reading the Arbin file requires MDBTools"
+)
+@pytest.mark.parametrize("basename", ["arbin1", "UM34_Test005E"])
 def test_convert_Arbin_to_sqlite_function(testdata_dir, tmpdir, basename):
     """Convert an Arbin file to SQLite using the functional interface."""
-    res_file = os.path.join(testdata_dir, basename + '.res')
-    sqlite_file = os.path.join(str(tmpdir), basename + '.s3db')
+    res_file = os.path.join(testdata_dir, basename + ".res")
+    sqlite_file = os.path.join(str(tmpdir), basename + ".s3db")
     res2sqlite.convert_arbin_to_sqlite(res_file, sqlite_file)
     assert os.path.isfile(sqlite_file)
     with sqlite3.connect(sqlite_file) as conn:
-        csr = conn.execute('SELECT * FROM Channel_Normal_Table;')
+        csr = conn.execute("SELECT * FROM Channel_Normal_Table;")
         csr.fetchone()
 
 
-@pytest.mark.skipif(not have_mdbtools, reason='Reading the Arbin file requires MDBTools')
+@pytest.mark.skipif(
+    not have_mdbtools, reason="Reading the Arbin file requires MDBTools"
+)
 def test_convert_cmdline(testdata_dir, tmpdir):
     """Checks that the conversion fails with an appropriate error message."""
-    res_file = os.path.join(testdata_dir, 'arbin1.res')
-    sqlite_file = os.path.join(str(tmpdir), 'arbin1.s3db')
-    subprocess.check_call(['res2sqlite', res_file, sqlite_file])
+    res_file = os.path.join(testdata_dir, "arbin1.res")
+    sqlite_file = os.path.join(str(tmpdir), "arbin1.s3db")
+    subprocess.check_call(["res2sqlite", res_file, sqlite_file])
     assert os.path.isfile(sqlite_file)
     with sqlite3.connect(sqlite_file) as conn:
-        csr = conn.execute('SELECT * FROM Channel_Normal_Table;')
+        csr = conn.execute("SELECT * FROM Channel_Normal_Table;")
         csr.fetchone()
diff --git a/tests/test_BioLogic.py b/tests/test_BioLogic.py
index ad7be6f..df90b18 100644
--- a/tests/test_BioLogic.py
+++ b/tests/test_BioLogic.py
@@ -17,33 +17,55 @@ from galvani.BioLogic import MPTfileCSV  # not exported
 
 
 def test_open_MPT(testdata_dir):
-    mpt1, comments = MPTfile(os.path.join(testdata_dir, 'bio_logic1.mpt'))
+    mpt1, comments = MPTfile(os.path.join(testdata_dir, "bio_logic1.mpt"))
     assert comments == []
     assert mpt1.dtype.names == (
-        "mode", "ox/red", "error", "control changes", "Ns changes",
-        "counter inc.", "time/s", "control/V/mA", "Ewe/V", "dQ/mA.h", "P/W",
-        "I/mA", "(Q-Qo)/mA.h", "x",
+        "mode",
+        "ox/red",
+        "error",
+        "control changes",
+        "Ns changes",
+        "counter inc.",
+        "time/s",
+        "control/V/mA",
+        "Ewe/V",
+        "dQ/mA.h",
+        "P/W",
+        "I/mA",
+        "(Q-Qo)/mA.h",
+        "x",
     )
 
 
 def test_open_MPT_fails_for_bad_file(testdata_dir):
-    with pytest.raises(ValueError, match='Bad first line'):
-        MPTfile(os.path.join(testdata_dir, 'bio_logic1.mpr'))
+    with pytest.raises(ValueError, match="Bad first line"):
+        MPTfile(os.path.join(testdata_dir, "bio_logic1.mpr"))
 
 
 def test_open_MPT_csv(testdata_dir):
-    mpt1, comments = MPTfileCSV(os.path.join(testdata_dir, 'bio_logic1.mpt'))
+    mpt1, comments = MPTfileCSV(os.path.join(testdata_dir, "bio_logic1.mpt"))
     assert comments == []
     assert mpt1.fieldnames == [
-        "mode", "ox/red", "error", "control changes", "Ns changes",
-        "counter inc.", "time/s", "control/V/mA", "Ewe/V", "dq/mA.h", "P/W",
-        "<I>/mA", "(Q-Qo)/mA.h", "x",
+        "mode",
+        "ox/red",
+        "error",
+        "control changes",
+        "Ns changes",
+        "counter inc.",
+        "time/s",
+        "control/V/mA",
+        "Ewe/V",
+        "dq/mA.h",
+        "P/W",
+        "<I>/mA",
+        "(Q-Qo)/mA.h",
+        "x",
     ]
 
 
 def test_open_MPT_csv_fails_for_bad_file(testdata_dir):
     with pytest.raises((ValueError, UnicodeDecodeError)):
-        MPTfileCSV(os.path.join(testdata_dir, 'bio_logic1.mpr'))
+        MPTfileCSV(os.path.join(testdata_dir, "bio_logic1.mpr"))
 
 
 def test_colID_map_uniqueness():
@@ -59,13 +81,16 @@ def test_colID_map_uniqueness():
     assert not set(field_names).intersection(flag_names)
 
 
-@pytest.mark.parametrize('colIDs, expected', [
-    ([1, 2, 3], [('flags', 'u1')]),
-    ([4, 6], [('time/s', '<f8'), ('Ewe/V', '<f4')]),
-    ([1, 4, 21], [('flags', 'u1'), ('time/s', '<f8')]),
-    ([4, 6, 4], [('time/s', '<f8'), ('Ewe/V', '<f4'), ('time/s 2', '<f8')]),
-    ([4, 9999], NotImplementedError),
-])
+@pytest.mark.parametrize(
+    "colIDs, expected",
+    [
+        ([1, 2, 3], [("flags", "u1")]),
+        ([4, 6], [("time/s", "<f8"), ("Ewe/V", "<f4")]),
+        ([1, 4, 21], [("flags", "u1"), ("time/s", "<f8")]),
+        ([4, 6, 4], [("time/s", "<f8"), ("Ewe/V", "<f4"), ("time/s 2", "<f8")]),
+        ([4, 9999], NotImplementedError),
+    ],
+)
 def test_colID_to_dtype(colIDs, expected):
     """Test converting column ID to numpy dtype."""
     if isinstance(expected, type) and issubclass(expected, Exception):
@@ -77,14 +102,17 @@ def test_colID_to_dtype(colIDs, expected):
     assert dtype == expected_dtype
 
 
-@pytest.mark.parametrize('data, expected', [
-    ('02/23/17', date(2017, 2, 23)),
-    ('10-03-05', date(2005, 10, 3)),
-    ('11.12.20', date(2020, 11, 12)),
-    (b'01/02/03', date(2003, 1, 2)),
-    ('13.08.07', ValueError),
-    ('03-04/05', ValueError),
-])
+@pytest.mark.parametrize(
+    "data, expected",
+    [
+        ("02/23/17", date(2017, 2, 23)),
+        ("10-03-05", date(2005, 10, 3)),
+        ("11.12.20", date(2020, 11, 12)),
+        (b"01/02/03", date(2003, 1, 2)),
+        ("13.08.07", ValueError),
+        ("03-04/05", ValueError),
+    ],
+)
 def test_parse_BioLogic_date(data, expected):
     """Test the parse_BioLogic_date function."""
     if isinstance(expected, type) and issubclass(expected, Exception):
@@ -95,51 +123,54 @@ def test_parse_BioLogic_date(data, expected):
     assert result == expected
 
 
-@pytest.mark.parametrize('filename, startdate, enddate', [
-    ('bio_logic1.mpr', '2011-10-29', '2011-10-31'),
-    ('bio_logic2.mpr', '2012-09-27', '2012-09-27'),
-    ('bio_logic3.mpr', '2013-03-27', '2013-03-27'),
-    ('bio_logic4.mpr', '2011-11-01', '2011-11-02'),
-    ('bio_logic5.mpr', '2013-01-28', '2013-01-28'),
-    # bio_logic6.mpr has no end date because it does not have a VMP LOG module
-    ('bio_logic6.mpr', '2012-09-11', None),
-    # C019P-0ppb-A_C01.mpr stores the date in a different format
-    ('C019P-0ppb-A_C01.mpr', '2019-03-14', '2019-03-14'),
-    ('Rapp_Error.mpr', '2010-12-02', '2010-12-02'),
-    ('Ewe_Error.mpr', '2021-11-18', '2021-11-19'),
-])
+@pytest.mark.parametrize(
+    "filename, startdate, enddate",
+    [
+        ("bio_logic1.mpr", "2011-10-29", "2011-10-31"),
+        ("bio_logic2.mpr", "2012-09-27", "2012-09-27"),
+        ("bio_logic3.mpr", "2013-03-27", "2013-03-27"),
+        ("bio_logic4.mpr", "2011-11-01", "2011-11-02"),
+        ("bio_logic5.mpr", "2013-01-28", "2013-01-28"),
+        # bio_logic6.mpr has no end date because it does not have a VMP LOG module
+        ("bio_logic6.mpr", "2012-09-11", None),
+        # C019P-0ppb-A_C01.mpr stores the date in a different format
+        ("C019P-0ppb-A_C01.mpr", "2019-03-14", "2019-03-14"),
+        ("Rapp_Error.mpr", "2010-12-02", "2010-12-02"),
+        ("Ewe_Error.mpr", "2021-11-18", "2021-11-19"),
+    ],
+)
 def test_MPR_dates(testdata_dir, filename, startdate, enddate):
     """Check that the start and end dates in .mpr files are read correctly."""
     mpr = MPRfile(os.path.join(testdata_dir, filename))
-    assert mpr.startdate.strftime('%Y-%m-%d') == startdate
+    assert mpr.startdate.strftime("%Y-%m-%d") == startdate
     if enddate:
-        assert mpr.enddate.strftime('%Y-%m-%d') == enddate
+        assert mpr.enddate.strftime("%Y-%m-%d") == enddate
     else:
-        assert not hasattr(mpr, 'enddate')
+        assert not hasattr(mpr, "enddate")
 
 
 def test_open_MPR_fails_for_bad_file(testdata_dir):
-    with pytest.raises(ValueError, match='Invalid magic for .mpr file'):
-        MPRfile(os.path.join(testdata_dir, 'arbin1.res'))
+    with pytest.raises(ValueError, match="Invalid magic for .mpr file"):
+        MPRfile(os.path.join(testdata_dir, "arbin1.res"))
 
 
 def timestamp_from_comments(comments):
     for line in comments:
-        time_match = re.match(b'Acquisition started on : ([0-9/]+ [0-9:]+)', line)
+        time_match = re.match(b"Acquisition started on : ([0-9/]+ [0-9:]+)", line)
         if time_match:
-            timestamp = datetime.strptime(time_match.group(1).decode('ascii'),
-                                          '%m/%d/%Y %H:%M:%S')
+            timestamp = datetime.strptime(
+                time_match.group(1).decode("ascii"), "%m/%d/%Y %H:%M:%S"
+            )
             return timestamp
     raise AttributeError("No timestamp in comments")
 
 
 def assert_MPR_matches_MPT(mpr, mpt, comments):
-
     def assert_field_matches(fieldname, decimal):
         if fieldname in mpr.dtype.fields:
-            assert_array_almost_equal(mpr.data[fieldname],
-                                      mpt[fieldname],
-                                      decimal=decimal)
+            assert_array_almost_equal(
+                mpr.data[fieldname], mpt[fieldname], decimal=decimal
+            )
 
     def assert_field_exact(fieldname):
         if fieldname in mpr.dtype.fields:
@@ -154,16 +185,16 @@ def assert_MPR_matches_MPT(mpr, mpt, comments):
     # Nothing uses the 0x40 bit of the flags
     assert_array_equal(mpr.get_flag("counter inc."), mpt["counter inc."])
 
-    assert_array_almost_equal(mpr.data["time/s"],
-                              mpt["time/s"],
-                              decimal=2)  # 2 digits in CSV
+    assert_array_almost_equal(
+        mpr.data["time/s"], mpt["time/s"], decimal=2
+    )  # 2 digits in CSV
 
     assert_field_matches("control/V/mA", decimal=6)
     assert_field_matches("control/V", decimal=6)
 
-    assert_array_almost_equal(mpr.data["Ewe/V"],
-                              mpt["Ewe/V"],
-                              decimal=6)  # 32 bit float precision
+    assert_array_almost_equal(
+        mpr.data["Ewe/V"], mpt["Ewe/V"], decimal=6
+    )  # 32 bit float precision
 
     assert_field_matches("dQ/mA.h", decimal=16)  # 64 bit float precision
     assert_field_matches("P/W", decimal=10)  # 32 bit float precision for 1.xxE-5
@@ -178,39 +209,45 @@ def assert_MPR_matches_MPT(mpr, mpt, comments):
         pass
 
 
-@pytest.mark.parametrize('basename', [
-    'bio_logic1',
-    'bio_logic2',
-    # No bio_logic3.mpt file
-    'bio_logic4',
-    # bio_logic5 and bio_logic6 are special cases
-    'CV_C01',
-    '121_CA_455nm_6V_30min_C01',
-    '020-formation_CB5',
-])
+@pytest.mark.parametrize(
+    "basename",
+    [
+        "bio_logic1",
+        "bio_logic2",
+        # No bio_logic3.mpt file
+        "bio_logic4",
+        # bio_logic5 and bio_logic6 are special cases
+        "CV_C01",
+        "121_CA_455nm_6V_30min_C01",
+        "020-formation_CB5",
+    ],
+)
 def test_MPR_matches_MPT(testdata_dir, basename):
     """Check the MPR parser against the MPT parser.
 
     Load a binary .mpr file and a text .mpt file which should contain
     exactly the same data. Check that the loaded data actually match.
     """
-    binpath = os.path.join(testdata_dir, basename + '.mpr')
-    txtpath = os.path.join(testdata_dir, basename + '.mpt')
+    binpath = os.path.join(testdata_dir, basename + ".mpr")
+    txtpath = os.path.join(testdata_dir, basename + ".mpt")
     mpr = MPRfile(binpath)
-    mpt, comments = MPTfile(txtpath, encoding='latin1')
+    mpt, comments = MPTfile(txtpath, encoding="latin1")
     assert_MPR_matches_MPT(mpr, mpt, comments)
 
 
 def test_MPR5_matches_MPT5(testdata_dir):
-    mpr = MPRfile(os.path.join(testdata_dir, 'bio_logic5.mpr'))
-    mpt, comments = MPTfile((re.sub(b'\tXXX\t', b'\t0\t', line) for line in
-                             open(os.path.join(testdata_dir, 'bio_logic5.mpt'),
-                                  mode='rb')))
+    mpr = MPRfile(os.path.join(testdata_dir, "bio_logic5.mpr"))
+    mpt, comments = MPTfile(
+        (
+            re.sub(b"\tXXX\t", b"\t0\t", line)
+            for line in open(os.path.join(testdata_dir, "bio_logic5.mpt"), mode="rb")
+        )
+    )
     assert_MPR_matches_MPT(mpr, mpt, comments)
 
 
 def test_MPR6_matches_MPT6(testdata_dir):
-    mpr = MPRfile(os.path.join(testdata_dir, 'bio_logic6.mpr'))
-    mpt, comments = MPTfile(os.path.join(testdata_dir, 'bio_logic6.mpt'))
+    mpr = MPRfile(os.path.join(testdata_dir, "bio_logic6.mpr"))
+    mpt, comments = MPTfile(os.path.join(testdata_dir, "bio_logic6.mpt"))
     mpr.data = mpr.data[:958]  # .mpt file is incomplete
     assert_MPR_matches_MPT(mpr, mpt, comments)