added a fall back to repr, and tests

Author: BalzaniEdoardo

src/nemos/utils.py

@@ -534,7 +534,7 @@ def format_repr(
         )
         if repr_param:
             if k in use_name_keys:
-                v = v.__name__
+                v = getattr(v, "__name__", repr(v))
             elif isinstance(v, str):
                 v = repr(v)
             disp_params.append(f"{k}={v}")

tests/test_utils.py

@@ -1,5 +1,6 @@
 import warnings
 from contextlib import nullcontext as does_not_raise
+from copy import deepcopy
 
 import jax
 import jax.numpy as jnp
@@ -595,6 +596,8 @@ def __repr__(self):
         (Example(a=0, b=False, c=None), None, [], "Example(a=0, b=False, d=1)"),
         # Falsey values excluded2
         (Example(a=0, b=[], c={}), None, [], "Example(a=0, d=1)"),
+        # function without the __name__
+        (nmo.observation_models.PoissonObservations(deepcopy(jax.numpy.exp)),None, [], "PoissonObservations(inverse_link_function=<PjitFunction>)")
     ],
 )
 def test_format_repr(obj, exclude_keys, use_name_keys, expected):