Raise when data is both specification and section

tests/parse/test_parse_vrplib.py

@@ -231,6 +231,24 @@ def test_parse_vrplib_do_not_compute_edge_weights():
  assert_("edge_weight" not in actual)
 
 
+def test_parse_vrplib_raises_when_both_specification_and_section():
+ """
+ Tests if a ValueError is raised when a specification is also a section.
+ """
+ instance = "\n".join(
+ [
+ "SERVICE_TIME: 10",
+ "SERVICE_TIME_SECTION",
+ "1 20",
+ "2 20",
+ ]
+ )
+
+ # Service time is both a specification and a section which is not allowed.
+ with assert_raises(ValueError):
+ parse_vrplib(instance)
+
+
 def test_empty_text():
  """
  Tests if an empty text file is still read correctly.

vrplib/parse/parse_vrplib.py

@@ -43,6 +43,12 @@ def parse_vrplib(text: str, compute_edge_weights: bool = True) -> Instance:
 
  for section in sections:
  section_name, data = parse_section(section, instance)
+
+ if section_name in instance:
+ name = section_name.upper()
+ msg = f"{name} is used both as a specification and a section."
+ raise ValueError(msg)
+
  instance[section_name] = data # type: ignore
 
  if instance and compute_edge_weights and "edge_weight" not in instance: