def _create_file_if_needed(self):
        if not os.path.exists(self._file.filename()):
            old_umask = os.umask(0o177)
            try:
                open(self._file.filename(), 'a+b').close()
            finally:
                os.umask(old_umask)
Creates the minor matrix of a given element.
dataset/ETHPy150Open google/oauth2client/oauth2client/contrib/multistore_file.py/_MultiStore._create_file_if_needed--crossover with--dataset/ETHPy150Open sympy/sympy/sympy/matrices/matrices.py/MatrixBase.minorMatrix