Saves pypesto and python version to the problem.

pypesto/problem/base.py

@@ -1,5 +1,6 @@
 import copy
 import logging
+import sys
 from collections.abc import Iterable
 from typing import (
     Callable,
@@ -15,6 +16,7 @@
 from ..objective import ObjectiveBase
 from ..objective.priors import NegLogParameterPriors
 from ..startpoint import StartpointMethod, to_startpoint_method, uniform
+from ..version import __version__
 
 SupportsFloatIterableOrValue = Union[Iterable[SupportsFloat], SupportsFloat]
 SupportsIntIterableOrValue = Union[Iterable[SupportsInt], SupportsInt]
@@ -164,6 +166,9 @@ def __init__(
             startpoint_method = uniform
         # convert startpoint method to class instance
         self.startpoint_method = to_startpoint_method(startpoint_method)
+        # save python and pypesto version
+        self.python_version = ".".join(map(str, sys.version_info[:3]))
+        self.pypesto_version = __version__
 
     @property
     def lb(self) -> np.ndarray:

pypesto/store/save_to_hdf5.py

@@ -92,7 +92,7 @@ def write(self, problem, overwrite: bool = False):
                     value = np.asarray(value)
                     if value.size:
                         write_array(problem_grp, problem_attr, value)
-                elif isinstance(value, Integral):
+                elif isinstance(value, (Integral, str)):
                     problem_grp.attrs[problem_attr] = value