fix #7053 by casting to string, removing obsolete item() call. (#7054)
fix #7053 by casting to string, removing obsolete item() call. (#7054)


twosigma/beakerx,jpallas/beakerx,jpallas/beakerx,twosigma/beaker-notebook,twosigma/beakerx,twosigma/beakerx,twosigma/beaker-notebook,jpallas/beakerx,twosigma/beaker-notebook,twosigma/beakerx,twosigma/beakerx,twosigma/beaker-notebook,twosigma/beaker-notebook,twosigma/beakerx,jpallas/beakerx,jpallas/beakerx,jpallas/beakerx