@step(u'a file named "{filename}" exists')
def step_file_named_filename_exists(context, filename):
 step_file_named_filename_should_exist(context, filename)

@ step ( u'a file named "{filename}" exists' ) def step_file_named_filename_exists ( context , filename ) : step_file_named_filename_should_exist ( context , filename )
verifies that a file with this filename exists .