#文件的读写模式，r w x a b t +
def read_file():
text = 'test.text'
with open(text,encoding='utf-8') as r:#自动关闭文件，可以使用完全路径
rest = r.read()#将对象读取成为文件
readline只读一行
readlines读取所有行 以列表形式出现
print(rest)
if name=='main':
read_file()

#文件的写入
def write_file():#逐个写入
    file_name = 'test1'
    f = open(file_name,'w')#以写入的方式打开文件
    f.write('hello')
    f.write('\n')
    f.write('world')
def write_mult_line():#一次性写入
    file_name = 'write_mult_line.txt'
    with open(file_name,'w',encoding='utf-8') as f:
        l = ['1','2','3']
        f.writelines(l)
def write_user_log():#随机记录时间和用户并且逐行写入
    rest = '用户：{0} - 访问时间{1}'.format(random.randint(1000,9999), datetime.now())
    print(rest)
    file_name = 'write_user_log.txt'
    with open(file_name,'a',encoding='utf-8') as f:
        f.write(rest)
        f.write('\n')
def read_and_write():#先读再写入  判断是否有某个字符串
    file_name = 'read_and_write'  #这个需要先建立文件夹
    with open(file_name,'r+',encoding='utf-8') as f:
        read_rest = f.read()
        if '1' in read_rest:
            f.write('kkkkkkkk')
        else:
            f.write('aaaa')
        f.write('\n')

if __name__ == '__main__':
    read_and_write()