第一部分day5 文件操作

#-----文件操作-----

文件操作模式 1、"r" 读 2、"w" 清空写入 3、"a" 追加 4、"r+" 读写模式，可读可写 5、"w+" 写读模式，可写可读 6、"a+" 追加模式

 with open("小重山","r",encoding="utf-8") as f:
     data = f.read()
     print(data)
     f.close()

readlines 方法

 with open("小重山","r",encoding="utf-8") as f:
     data = f.readlines()
     for i in data:
         print(i.strip())

 with open("小重山1","w",encoding="utf-8") as f:
     f.write("昨夜寒蛩不住鸣。惊回千里梦，已三更。起来独自绕阶行。")

#在文件中第6行操作

 with open("小重山","r",encoding="utf-8") as f:
     # print(f.fileno()) #文件句柄 #3
     num1 = 0
     for i in f.readlines():
         num1 += 1
         if num1 == 6:
             i = ''.join([i.strip(),'ok'])
         print(i.strip())

 with open("小重山","r",encoding="utf-8") as f:
     num1 = 0
     for i in f:  #for循环内部将f 对象做成一个迭代器，用一行取一行
         num1 += 1
         if num1 == 4:
             i = "".join([i.strip(),"ok"])
         print(i.strip())

#flush 方法（简单版进度条）

 import time,sys

 for i in range(30):
     sys.stdout.write("*")
     time.sleep(0.2)
     sys.stdout.flush()

 for i in range(30):
     print("*",end="",flush=True)
     time.sleep(0.2)

#truncate 截断

 with open("小重山1","a",encoding="utf-8") as f:
     f.truncate(6) #昨夜

#r+ 模式 光标以起始0开始

 with open("小重山1","a+",encoding="utf-8") as f:
     f.write("岳飞") #写入文件最后
     f.close()

#w+ 模式

 with open("小重山1","w+",encoding="utf-8") as f:
     f.write("岳飞")
     print(f.tell()) #
     f.seek(0)
     print(f.readline())

#a+ 模式 光标以末尾开始

 with open("小重山1","a+",encoding="utf-8") as f:
     print(f.tell())
     f.write("岳飞")
     print(f.tell())
     print(f.readline())

#文件修改

 # f_read = open("小重山1",'r',encoding="utf-8")
 # f_write = open("小重山2",'w',encoding="utf-8")
 #with 同时管理多个文件对象
 with open("小重山1",'r',encoding="utf-8") as f_read,open("小重山2",'w',encoding="utf-8") as f_write:
     num1 = 0
     for line in f_read:
         num1 += 1
         if num1 == 5:
             line = "".join([line.strip(),"dream\n"])
         f_write.write(line)
         print(line.strip())
     f_write.close()
     f_read.close()