Python读取文件时出现UnicodeDecodeError

运行下面code时

with open('style.css','r',encoding='utf-8') as f:
	for line in f:
		print(line)

出现错误

UnicodeDecodeError: 'gbk' codec can't decode byte 0x9d in position 1947: illegal multibyte sequence

将open代码改为

with open('style.css','r',encoding='utf-8') as f:
	for line in f:
		print(line)