[已解决]请教：想实现连续的字符替换，但一次可以，多次就不行了，不知道为什么？

lemon_wb

1. import re   #引用re模块
   
2. 
   
3. f1=open("C:\\Users\\Administrator\\Desktop\\2.txt","r")
   
4. content=f1.read()
   
5. f1.close()
   
6. 
   
7. t=content.replace("\n\n","换行")
   
8. t=content.replace("\n","")
   
9. t=content.replace("换行","\n")
   
10. with open("C:\\Users\\Administrator\\Desktop\\2.txt","w") as f2:
    
11.     f2.write(t)

复制代码

编写了这段代码，想实现三次字符替换，但运行后仅能实现最后一次的替换，想不明白为什么？

然后把程序改成了

1. import re   #引用re模块
   
2. 
   
3. f1=open("C:\\Users\\Administrator\\Desktop\\2.txt","r")
   
4. content=f1.read()
   
5. f1.close()
   
6. 
   
7. t=content.replace("\n\n","换行")
   
8. with open("C:\\Users\\Administrator\\Desktop\\2.txt","w") as f2:
   
9.     f2.write(t)
   
10. t=content.replace("\n","")
    
11. with open("C:\\Users\\Administrator\\Desktop\\2.txt","w") as f2:
    
12.     f2.write(t)
    
13. t=content.replace("换行","\n")
    
14. with open("C:\\Users\\Administrator\\Desktop\\2.txt","w") as f2:
    
15.     f2.write(t)

复制代码

效果还是一样的。
必须打开一次文件只替换一次字符，运行三次才可以实现最终要的效果。
请教各位大神，程序应该怎么改，才能运行一次就能实现三次字符替换呢？

最佳答案

月排行榜 / 总排行榜

永恒的蓝色梦想

2020-5-14 14:27:17

1. import re   #引用re模块
   
2. 
   
3. f1=open("C:\\Users\\Administrator\\Desktop\\2.txt","r")
   
4. content=f1.read()
   
5. f1.close()
   
6. 
   
7. t=content.replace("\n\n","换行")
   
8. t=t.replace("\n","")
   
9. t=t.replace("换行","\n")
   
10. with open("C:\\Users\\Administrator\\Desktop\\2.txt","w") as f2:
    
11.     f2.write(t)

复制代码

跳转到最佳答案楼层

永恒的蓝色梦想

1. import re   #引用re模块
   
2. 
   
3. f1=open("C:\\Users\\Administrator\\Desktop\\2.txt","r")
   
4. content=f1.read()
   
5. f1.close()
   
6. 
   
7. t=content.replace("\n\n","换行")
   
8. t=t.replace("\n","")
   
9. t=t.replace("换行","\n")
   
10. with open("C:\\Users\\Administrator\\Desktop\\2.txt","w") as f2:
    
11.     f2.write(t)

复制代码

永恒的蓝色梦想

说实话，你这错误出的，不明显么？

xiaosi4081

永恒的蓝色梦想 发表于 2020-5-14 14:28
说实话，你这错误出的，不明显么？

同感

lemon_wb

谢谢指教
明白了