f = open('user.txt','r') #文件句柄
f1 = open('user.txt','w') #覆盖写入
f2 = open('user.txt','a') #追加到文件内容到末尾
with open('user.txt','r') as f: #自动关闭文件
pass
#读写模式
1 f = open('user.txt','r+') #读写
2 print(f.readline().strip())
3 print(f.readline().strip())
4 print(f.readline().strip())
5 f.write("\n------------")
6 f.tell() #获取当前文件读取指针的位置
7 f.seek(0) #用于移动文件读写指针到指定的位置
#修改文件
1 f = open('user.txt','r')#读写
2 f_2 = open('simple.txt','w')
3
4 for i in f:
5 if 'xxxxxxx' in i:
6 i = i.replace("xxxxxxx","55444")
7 f_2.write(i)
8 f.close()
9 f_2.close()
#修改文件2
1 with open('user.txt','r') as f,\
2 open('simple.txt','w') as f_2:
3 for i in f:
4 if 'xxxxxxx' in i:
5 i = i.replace("xxxxxxx","111111111")
6 f_2.write(i)
#打印几行
for i in range(1,5):
print(f.readline().strip())
#跳过第二行,如果文件过大readlines会占用大量内存
1 for index,line in enumerate(f.readlines()):
2 if index == 2:
3 continue
4 print(index, line.strip())
#高效的循环
1 count = 0
2 for line in f:
3 count += 1
4 if count == 2:
5 print("-----替代-----")
6 continue
7 print(line.strip())
