#-----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
1 with open("小重山","r",encoding="utf-8") as f:
2 data = f.read()
3 print(data)
4 f.close()
readlines 方法
1 with open("小重山","r",encoding="utf-8") as f:
2 data = f.readlines()
3 for i in data:
4 print(i.strip())
5
6 with open("小重山1","w",encoding="utf-8") as f:
7 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
1 with open("小重山","r",encoding="utf-8") as f:
2 # print(f.fileno()) #文件句柄 #3
3 num1 = 0
4 for i in f.readlines():
5 num1 += 1
6 if num1 == 6:
7 i = ''.join([i.strip(),'ok'])
8 print(i.strip())
9
10 with open("小重山","r",encoding="utf-8") as f:
11 num1 = 0
12 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
13 num1 += 1
14 if num1 == 4:
15 i = "".join([i.strip(),"ok"])
16 print(i.strip())
#flush 方法（简单版进度条）
1 import time,sys
2
3 for i in range(30):
4 sys.stdout.write("*")
5 time.sleep(0.2)
6 sys.stdout.flush()
7
8 for i in range(30):
9 print("*",end="",flush=True)
10 time.sleep(0.2)
#truncate 截断
1 with open("小重山1","a",encoding="utf-8") as f:
2 f.truncate(6) #昨夜
#r+ 模式 光标以起始0开始
1 with open("小重山1","a+",encoding="utf-8") as f:
2 f.write("岳飞") #写入文件最后
3 f.close()
#w+ 模式
1 with open("小重山1","w+",encoding="utf-8") as f:
2 f.write("岳飞")
3 print(f.tell()) #6
4 f.seek(0)
5 print(f.readline())
#a+ 模式 光标以末尾开始
1 with open("小重山1","a+",encoding="utf-8") as f:
2 print(f.tell())
3 f.write("岳飞")
4 print(f.tell())
5 print(f.readline())
#文件修改
1 # f_read = open("小重山1",'r',encoding="utf-8")
2 # f_write = open("小重山2",'w',encoding="utf-8")
3 #with 同时管理多个文件对象
4 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:
5 num1 = 0
6 for line in f_read:
7 num1 += 1
8 if num1 == 5:
9 line = "".join([line.strip(),"dream\n"])
10 f_write.write(line)
11 print(line.strip())
12 f_write.close()
13 f_read.close()
