Fix string parsing regressions

CHANGELOG.rst

@@ -31,8 +31,9 @@ Fixed
   <https://github.com/omni-us/jsonargparse/pull/668>`__)
 - Functions that create types now have ``TypeAlias`` return type to avoid mypy
   errors (`#671 <https://github.com/omni-us/jsonargparse/pull/671>`__).
-- Bug when parsing strings with digits and a starting or ending 'e' (`#672
-  <https://github.com/omni-us/jsonargparse/pull/673>`__).
+- String parsing regressions (`#673
+  <https://github.com/omni-us/jsonargparse/pull/673>`__, `#674
+  <https://github.com/omni-us/jsonargparse/pull/674>`__).
 
 
 v4.36.0 (2025-01-17)

jsonargparse/_loaders_dumpers.py

@@ -28,15 +28,15 @@
         return False
     if value == "null":
         return None
-    if value.isdigit() or (value.startswith("-") and value[1:].isdigit()):
-        return int(value)
-    if (
-        not value.startswith("e")
-        and not value.endswith("e")
-        and value.replace(".", "", 1).replace("e", "", 1).replace("-", "", 2).isdigit()
-        and ("e" in value or "." in value)
-    ):
-        return float(value)
+    try:
+        if value.isdigit() or (value.startswith("-") and value[1:].isdigit()):
+            return int(value)
+        if value.replace(".", "", 1).replace("e", "", 1).replace("-", "", 2).isdigit() and (
+            "e" in value or "." in value
+        ):
+            return float(value)
+    except ValueError:
+        pass
     return not_loaded
 
 

jsonargparse/_typehints.py

@@ -602,11 +602,20 @@ def _check_type(self, value, append=False, cfg=None):
                     val["__path__"] = config_path
                 value[num] = val
             except (TypeError, ValueError) as ex:
-                elem = "" if not islist else f" element {num+1}"
-                error = indent_text(str(ex))
-                raise TypeError(f'Parser key "{self.dest}"{elem}:\n{error}') from ex
+                if self._is_valid_string(val):
+                    value[num] = val
+                else:
+                    elem = "" if not islist else f" element {num+1}"
+                    error = indent_text(str(ex))
+                    raise TypeError(f'Parser key "{self.dest}"{elem}:\n{error}') from ex
         return value if islist else value[0]
 
+    def _is_valid_string(self, value):
+        typehint = self._typehint
+        return isinstance(value, str) and (
+            typehint is str or (get_typehint_origin(typehint) == Union and str in typehint.__args__)
+        )
+
     def instantiate_classes(self, value):
         islist = _is_action_value_list(self)
         if not islist:

jsonargparse_tests/test_loaders_dumpers.py

@@ -91,12 +91,6 @@ def test_dump_header_invalid(parser):
         parser.dump_header = True
 
 
-def test_load_value_digits_and_e():
-    with parser_context(load_value_mode="yaml"):
-        assert "e123" == load_value("e123")
-        assert "123e" == load_value("123e")
-
-
 @skip_if_no_pyyaml
 def test_load_value_dash():
     with parser_context(load_value_mode="yaml"):

jsonargparse_tests/test_typehints.py

@@ -109,6 +109,15 @@ def test_str_yaml_constructor_error(parser):
     assert "{{something}}" == parser.parse_args(["--val={{something}}"]).val
 
 
+@parser_modes
+def test_str_edge_cases(parser):
+    parser.add_argument("--val", type=str)
+    assert parser.parse_args(["--val=e123"]).val == "e123"
+    assert parser.parse_args(["--val=123e"]).val == "123e"
+    val = "1" * 5000
+    assert parser.parse_args([f"--val={val}"]).val == val
+
+
 def test_bool_parse(parser):
     parser.add_argument("--val", type=bool)
     assert None is parser.get_defaults().val