f.write无法记录输入

Question

假设这样的文本

In [134]: !cat test1.md                                                                                           
The first test

我打开并写内容

In [156]: f1 = open("test1.md", "r+")                                                                             

In [157]: f1.write("The second test")                                                                             
Out[157]: 15

In [158]: !cat test1.md                                                                                           
The first test
test second method

如果继续执行input

，它直到现在仍可以正常工作。

In [159]: f1.write("The third test")                                                                              
Out[159]: 14

In [160]: !cat test1.md                                                                                           
The first test
test second method


In [161]: f1.write("The fourth  test")                                                                            
Out[161]: 16

In [162]: !cat test1.md                                                                                           
The first test
test second method

f.write有什么问题？。

Answer 1

您需要先flush()缓冲区，然后close()文件。也可以将您的字符串附加到文件中。

f1 = open("test1.md", "a") # "a" means append to file                                                                          

f1.write("The second test")
f1.flush()
f1.close()

cat文件；

cat test1.md                                                                                           

The first test
test second method

---

正确的方式。

您应该真的像这样做

with open("test1.md", "a") as f1:
    f1.write("The second test")
    f1.flush()
    f1.close()