diff --git a/src/scgenerator/__init__.py b/src/scgenerator/__init__.py
index d5e5c7b..4c9e73d 100644
--- a/src/scgenerator/__init__.py
+++ b/src/scgenerator/__init__.py
@@ -4,5 +4,5 @@ from .physics import fiber, materials, pulse, simulate, units
 from .physics.simulate import RK4IP, parallel_RK4IP, run_simulation
 from .plotting import mean_values_plot, plot_spectrogram, propagation_plot, single_position_plot
 from .spectra import Pulse, Spectrum
-from .utils import Paths, open_config
+from .utils import Paths, open_config, parameter
 from .utils.parameter import Configuration, Parameters, PlotRange
diff --git a/src/scgenerator/utils/__init__.py b/src/scgenerator/utils/__init__.py
index b3296ac..9ca5ac3 100644
--- a/src/scgenerator/utils/__init__.py
+++ b/src/scgenerator/utils/__init__.py
@@ -116,7 +116,7 @@ def open_config(path: os.PathLike):
 
     dico.setdefault("variable", {})
     for key in {"simulation", "fiber", "gas", "pulse"} & dico.keys():
-        section = dico.pop(key, {})
+        section = dico.pop(key)
         dico["variable"].update(section.pop("variable", {}))
         dico.update(section)
     if len(dico["variable"]) == 0:
diff --git a/src/scgenerator/utils/parameter.py b/src/scgenerator/utils/parameter.py
index 53bb8b5..6822aa7 100644
--- a/src/scgenerator/utils/parameter.py
+++ b/src/scgenerator/utils/parameter.py
@@ -1227,11 +1227,21 @@ def format_variable_list(l: list[tuple[str, Any]], add_iden=False) -> str:
     tmp_name = PARAM_SEPARATOR.join(str_list)
     if not add_iden:
         return tmp_name
-    unique_id = "u_" + utils.to_62(hash(str(l)))
-    branch_id = "b_" + utils.to_62(hash(str([el for el in l if el[0] != "num"])))
+    unique_id = unique_identifier(l)
+    branch_id = branch_identifier(l)
     return unique_id + PARAM_SEPARATOR + branch_id + PARAM_SEPARATOR + tmp_name
 
 
+def branch_identifier(l):
+    branch_id = "b_" + utils.to_62(hash(str([el for el in l if el[0] != "num"])))
+    return branch_id
+
+
+def unique_identifier(l):
+    unique_id = "u_" + utils.to_62(hash(str(l)))
+    return unique_id
+
+
 def format_value(name: str, value) -> str:
     if value is True or value is False:
         return str(value)