读相关操作

readline

# 1、readline：一次读一行
with open(r'g.txt', mode='rt', encoding='utf-8') as f:
    while True:
        line = f.readline()
        if len(line) == 0:
            break
        print(line)

readlines

with open(r'g.txt', mode='rt', encoding='utf-8') as f:
    res = f.readlines()        # 生成一个列表
    print(res)

写相关操作

writelines

with open('h.txt', mode='wt', encoding='utf-8') as f:
    # f.write('1111\n222\n3333\n')
    # l=['11111\n','2222','3333',4444]
    l = ['11111\n', '2222', '3333']
    # for line in l:
    #     f.write(line)
    f.writelines(l)

with open('h.txt', mode='wb') as f:
    # l = [
    #     '1111aaa1\n'.encode('utf-8'),
    #     '222bb2'.encode('utf-8'),
    #     '33eee33'.encode('utf-8')
    # ]
    # 补充1：如果是纯英文字符，可以直接加前缀b得到bytes类型
    # l = [
    #     b'1111aaa1\n',
    #     b'222bb2',
    #     b'33eee33'
    # ]
    # 补充2：'上'.encode('utf-8') 等同于bytes('上',encoding='utf-8')
    l = [
        bytes('上啊', encoding='utf-8'),
        bytes('冲呀', encoding='utf-8'),
        bytes('小垃圾们', encoding='utf-8'),
    ]
    f.writelines(l)

flush

flush() 方法是用来刷新缓冲区的，即将缓冲区中的数据立刻写入文件，同时清空缓冲区，不需要是被动的等待输出缓冲区写入。
一般情况下，文件关闭后会自动刷新缓冲区，但有时你需要在关闭前刷新它，这时就可以使用 flush() 方法。
一般用于测试

with open('h.txt', mode='wt',encoding='utf-8') as f:
    f.write('哈')
    f.flush()

# 4、了解
with open('h.txt', mode='wt', encoding='utf-8') as f:
    print(f.readable())  # False
    print(f.writable())  # True
    print(f.encoding)  # utf-8
    print(f.name)  # h.txt
print(f.closed)  # True