About the order in which Python folders are written

Asked 2 months ago, Updated 2 months ago, 2 views

I would like to ask you about the order in which Python folders are written.
If you run the following sample, you will see

importos

def asxmake(srcDir):
    for subinos.listdir(srcDir):
        newSrcPath=os.path.join(srcDir, sub)
        ifos.path.isdir(newSrcPath):
            f=open(AsxMake, 'a+')
            print>>f, sub
            print sub
            asxmake (newSrcPath)

        else:
            f=open(AsxMake, 'a+')
            file=sub.replace('/', '\\')
            filename = os.path.basename(file)
            print>>f, sub
            print sub

srcDir='C:\\temp\\test'
AsxMakefall='C:\\temp\\test'
AsxMake='C:\\temp\\test\\1.asx'
asxmake(srcDir)

If you look at the written file, you can see

(The top tier is 01.txt02.txt
We are testing with 03.txt04.txt in the 00 folder structure.)

US>03.txt
04.txt
00
US>01.txt
US>02.txt
It will be

If you look at the print statement, the order of processing is as follows.

00
US>03.txt
04.txt
US>01.txt
US>02.txt
What causes the order to change?

I am a beginner in the program, so I cannot find a solution.
I look forward to your kind cooperation.

python

2022-09-30 11:29

2 Answers

It is easy to understand if you keep in mind that the files are buffered.
Buffering is stored in memory before writing to a file, and when a certain amount is accumulated or the file is closed, it is written to a file.

This time, it is recursive, so the output of the recursive is written first.

00=>Buffer 1
  03.txt = > Buffer 2
  04.txt=>Buffer 2         
  Buffer 2 writeout
01.txt=>Buffer 1
02.txt = > Buffer 1
buffer 1 export

It is written in the order of buffer 2 and buffer 1, so the results are as described.
One way to get rid of this is to use flush.

def asxmake(srcDir):
    for subinos.listdir(srcDir):
        newSrcPath=os.path.join(srcDir, sub)
        ifos.path.isdir(newSrcPath):
            f=open(AsxMake, 'a+')
            print>>f, sub
            f.flush()
            print sub
            asxmake (newSrcPath)
        else:
            f=open(AsxMake, 'a+')
            file=sub.replace('/', '\\')
            filename = os.path.basename(file)
            print>>f, sub
            f.flush()
            print sub

However, I think it would be easier to use walk instead of opening the file every time.


2022-09-30 11:29

Once you open the file, you can use the same file handler to write it down.

importos

def asxmake(f,srcDir):
    for subinos.listdir(srcDir):
        newSrcPath=os.path.join(srcDir, sub)
        ifos.path.isdir(newSrcPath):
            print>>f, sub
            asxmake(f, newSrcPath)

        else:
            file=sub.replace('/', '\\')
            filename = os.path.basename(file)
            print>>f, sub

srcDir='C:\\temp\\test'
AsxMakefall='C:\\temp\\test'
AsxMake='C:\\temp\\test\\1.asx'

with open(AsxMake, 'w') as f:
    asxmake(f,srcDir)


2022-09-30 11:29

If you have any answers or tips


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