Formatting

* Adding black as dev dependency
* Formatting pina code
* Formatting tests

pina/utils.py

@@ -8,10 +8,11 @@ from .label_tensor import LabelTensor
 
 
 def custom_warning_format(
-        message, category, filename, lineno, file=None, line=None
-        ):
+    message, category, filename, lineno, file=None, line=None
+):
     return f"{filename}: {category.__name__}: {message}\n"
 
+
 def check_consistency(object, object_instance, subclass=False):
     """Helper function to check object inheritance consistency.
        Given a specific ``'object'`` we check if the object is
@@ -39,6 +40,7 @@ def check_consistency(object, object_instance, subclass=False):
         except AssertionError:
             raise ValueError(f"{type(obj).__name__} must be {object_instance}.")
 
+
 def labelize_forward(forward, input_variables, output_variables):
     """
     Wrapper decorator to allow users to enable or disable the use of
@@ -51,6 +53,7 @@ def labelize_forward(forward, input_variables, output_variables):
     :param output_variables: The problem output variables.
     :type output_variables: list[str] | tuple[str]
     """
+
     def wrapper(x):
         x = x.extract(input_variables)
         output = forward(x)
@@ -59,8 +62,10 @@ def labelize_forward(forward, input_variables, output_variables):
         output = output.as_subclass(LabelTensor)
         output.labels = output_variables
         return output
+
     return wrapper
 
+
 def merge_tensors(tensors):  # name to be changed
     if tensors:
         return reduce(merge_two_tensors, tensors[1:], tensors[0])
@@ -72,8 +77,9 @@ def merge_two_tensors(tensor1, tensor2):
     n2 = tensor2.shape[0]
 
     tensor1 = LabelTensor(tensor1.repeat(n2, 1), labels=tensor1.labels)
-    tensor2 = LabelTensor(tensor2.repeat_interleave(n1, dim=0),
-                          labels=tensor2.labels)
+    tensor2 = LabelTensor(
+        tensor2.repeat_interleave(n1, dim=0), labels=tensor2.labels
+    )
     return tensor1.append(tensor2)