Merge pull request #175 from ToFuProject/Issue174_RobustUnitsCheck

`'units'` are equal whether `str` or `asunits.Unit` when looking for conflicts

Author: Didou09

datastock/_class1_check.py

@@ -147,7 +147,14 @@ def _check_conflicts(dd=None, dd0=None, dd_name=None, returnas=None):
                     or (
                         not isinstance(v0[kk], np.ndarray)
                         and not scpsp.issparse(v0[kk])
-                        and v0[kk] == dd0[k0][kk]
+                        and (
+                            v0[kk] == dd0[k0][kk]
+                            or (
+                                # asunit.Unit vs str should be the same
+                                kk == 'units'
+                                and str(v0[kk]) == str(dd0[k0][kk])
+                            )
+                        )
                     )
                 )
             )
@@ -1925,4 +1932,4 @@ def _select(dd=None, dd_name=None, log=None, returnas=None, **kwdargs):
                 [k0 for jj, k0 in enumerate(dd.keys()) if ind[jj]],
                 dtype=str,
             )
-    return ind
+    return ind