Error when calling titers_long

[iAvicenna]

The following code throws an error

import os
import acorgdb 
from pathlib import Path

DB_DIR = Path(os.getenv("H5_MUTANTS"))
db = acorgdb.Database.from_dir(DB_DIR / "data")
db.titers_long

the error occurs specifically at

 df = (
            pd.melt(
                self.titers,
                ignore_index=False,
                var_name="serum",
                value_name="titer",
            )
            .eval(f"file = '{self.file}'")
            .reset_index()
        )

at the eval call when it says

ValueError: data type must provide an itemsize

Solution is to add to eval engine='python'. This should fixed in both the Experiment object and Result object.