Format code with black

This commit fixes the style issues introduced in d11773b according to the output
from black.

Details: https://deepsource.io/gh/MilesCranmer/PySR/transform/6e361fd3-a9c6-45c5-b5c5-df824cd0014c/

pysr/sr.py

@@ -367,9 +367,7 @@ def pysr(
     if maxsize < 7:
         raise NotImplementedError("PySR requires a maxsize of at least 7")
 
-    X, selection = _handle_feature_selection(
-        X, select_k_features, y, variable_names
-    )
+    X, selection = _handle_feature_selection(X, select_k_features, y, variable_names)
 
     if maxdepth is None:
         maxdepth = maxsize
@@ -657,9 +655,7 @@ def _create_inline_operators(binary_operators, unary_operators):
                 op_list[i] = function_name
 
 
-def _handle_feature_selection(
-    X, select_k_features, y, variable_names
-):
+def _handle_feature_selection(X, select_k_features, y, variable_names):
     if select_k_features is not None:
         selection = run_feature_selection(X, y, select_k_features)
         print(f"Using features {[variable_names[i] for i in selection]}")
@@ -801,7 +797,9 @@ def get_hof(
             sympy_format.append(eqn)
 
             # Numpy:
-            lambda_format.append(CallableEquation(sympy_symbols, eqn, selection, variable_names))
+            lambda_format.append(
+                CallableEquation(sympy_symbols, eqn, selection, variable_names)
+            )
 
             # JAX:
             if output_jax_format: