python读文件集中方式以及编码错误UnicodeDecodeError: 'gbk' codec can't decode byte 0x80 in position 12: illegal mu

s = ["您好\n","非常好\n","很高兴认识你\n"]
with open(r"C:\郑宏宇\python_learn\t.txt","w",encoding = "utf-8") as f:
    f.writelines(s)

#读取一个文件前4个字符

with open(r"C:\郑宏宇\python_learn\t.txt","r",encoding = "utf-8") as f:
    print(f.read(4))


#文件较小，一次将文件内容读入到程序中
with open(r"C:\郑宏宇\python_learn\t.txt","r",encoding = "utf-8") as f:
    print(f.read())

#按行读取一个文件
with open(r"C:\郑宏宇\python_learn\t.txt","r",encoding ="utf-8" ) as f:
    while True:
        fragment = f.readline()
        if not fragment:
            break
        else:
            print(fragment,end="")

#使用迭代器（每次返回一行）读取文本文件
with open(r"C:\郑宏宇\python_learn\t.txt","r",encoding = "utf-8") as f:
    for a in f:
        print(a,end="")

如果没有“encoding = "utf-8"就会报错