fix wrong file path check in python examples (#2252)
fix wrong file path check in python examples (#2252)

* fix wrong file path check in python examples

* fix typo
intel-analytics/BigDL,intel-analytics/BigDL,yangw1234/BigDL,yangw1234/BigDL,intel-analytics/BigDL,intel-analytics/BigDL,yangw1234/BigDL,yangw1234/BigDL