def is_file(self, file_name):

        """Check if a file exists on device"""

        self.shell_command(file_name % "ls %s")

        if self.stdout[0] == file_name:
            return True
        else:
            return False
dataset/ETHPy150Open jakev/dtf/src/dtf/adb.py/DtfAdb.is_file/swapped operands of `%`