diff --git a/altair/_magics.py b/altair/_magics.py
index 7fe613118..55b5b97e2 100644
--- a/altair/_magics.py
+++ b/altair/_magics.py
@@ -58,8 +58,9 @@ def _get_variable(name):
         )
     if name not in ip.user_ns:
         raise NameError(
-            "argument '{}' does not match the "
-            "name of any defined variable".format(name)
+            "argument '{}' does not match the " "name of any defined variable".format(
+                name
+            )
         )
     return ip.user_ns[name]
 
diff --git a/altair/utils/core.py b/altair/utils/core.py
index 28601db3c..4d2f9c7a5 100644
--- a/altair/utils/core.py
+++ b/altair/utils/core.py
@@ -380,18 +380,21 @@ def to_list_if_array(val):
             # geopandas >=0.6.1 uses the dtype geometry. Continue here
             # otherwise it will give an error on np.issubdtype(dtype, np.integer)
             continue
-        elif dtype_name in {
-            "Int8",
-            "Int16",
-            "Int32",
-            "Int64",
-            "UInt8",
-            "UInt16",
-            "UInt32",
-            "UInt64",
-            "Float32",
-            "Float64",
-        }:  # nullable integer datatypes (since 24.0) and nullable float datatypes (since 1.2.0)
+        elif (
+            dtype_name
+            in {
+                "Int8",
+                "Int16",
+                "Int32",
+                "Int64",
+                "UInt8",
+                "UInt16",
+                "UInt32",
+                "UInt64",
+                "Float32",
+                "Float64",
+            }
+        ):  # nullable integer datatypes (since 24.0) and nullable float datatypes (since 1.2.0)
             # https://pandas.pydata.org/pandas-docs/version/0.25/whatsnew/v0.24.0.html#optional-integer-na-support
             col = df[col_name].astype(object)
             df[col_name] = col.where(col.notnull(), None)
diff --git a/altair/utils/schemapi.py b/altair/utils/schemapi.py
index f38424681..f4b2e6b57 100644
--- a/altair/utils/schemapi.py
+++ b/altair/utils/schemapi.py
@@ -1079,7 +1079,7 @@ def from_json(
         cls,
         json_string: str,
         validate: bool = True,
-        **kwargs: Any
+        **kwargs: Any,
         # Type hints for this method would get rather complicated
         # if we want to provide a more specific return type
     ) -> Any:
diff --git a/sphinxext/utils.py b/sphinxext/utils.py
index 44b5074b2..f9dc181e9 100644
--- a/sphinxext/utils.py
+++ b/sphinxext/utils.py
@@ -122,8 +122,9 @@ def get_docstring_and_rest(filename):
 
     if not isinstance(node, ast.Module):
         raise TypeError(
-            "This function only supports modules. "
-            "You provided {}".format(node.__class__.__name__)
+            "This function only supports modules. " "You provided {}".format(
+                node.__class__.__name__
+            )
         )
     try:
         # In python 3.7 module knows its docstring.
diff --git a/tests/test_magics.py b/tests/test_magics.py
index db24ff480..4dd69ba7b 100644
--- a/tests/test_magics.py
+++ b/tests/test_magics.py
@@ -31,9 +31,7 @@
 import pandas as pd
 table = pd.DataFrame.from_records({})
 the_data = table
-""".format(
-            DATA_RECORDS
-        )
+""".format(DATA_RECORDS)
     )
 
 
diff --git a/tools/schemapi/schemapi.py b/tools/schemapi/schemapi.py
index af98fbe8c..f3e00e26a 100644
--- a/tools/schemapi/schemapi.py
+++ b/tools/schemapi/schemapi.py
@@ -1077,7 +1077,7 @@ def from_json(
         cls,
         json_string: str,
         validate: bool = True,
-        **kwargs: Any
+        **kwargs: Any,
         # Type hints for this method would get rather complicated
         # if we want to provide a more specific return type
     ) -> Any: