python 文件写入

def write_file():    """ 文件写入"""    file_name = "wri2te_test.txt"    # 以写入的方式打开    f = open(file_name,‘w‘)    # 写入内容    f.write(‘hello‘)    # 换行符    f.write(‘\n‘)    # 写入内容    f.write(‘world‘)

    # 关闭文件    f.close()

def write_mult_line():    """ 多行写入"""    file_name  = ‘write_mult_line.txt‘    with open(file_name, ‘w‘, encoding = ‘utf-8‘) as f:        # \r\n 换两行        # \n 换一行        l = [‘第1行‘,‘\n‘,‘第2行‘,‘\r\n‘,‘第3行‘,‘\n‘,‘第4行‘]        f.writelines(l)

import randomfrom datetime import  datetimedef write_user_log():    """  记录用户日志"""    rest = "用户: {0} - 访问时间 {1}".format(random.randint(1000,9999), datetime.now())    print (rest)

    file_name = ‘write_user_log.txt‘    # 追加    with open(file_name, ‘a‘, encoding = ‘utf-8‘) as f:        f.write(rest + ‘\n‘)

def read_and_write():    """ 先读，再写入"""    file_name = ‘read_and_write.txt‘    with open(file_name, ‘r+‘, encoding="utf-8") as f:        read_rest = f.read()        # 判断如果没有1 写一行 aaa        # 判断如果有1 写一行 bbb        if ‘1‘ in read_rest:            f.write(‘\n‘)            f.write(‘aaa‘)        else:            f.write(‘bbb‘)

if __name__ == ‘__main__‘:    # write_file()    # write_mult_line()    # write_user_log()    read_and_write()

原文地址：https://www.cnblogs.com/ericblog1992/p/11281432.html