Pass a value to the ftp.retrbinary callback

Question

I'm writing a module that uses FTPLib to fetch files. I want to find a way to pass a value(in addition to the block) to the callback. Essentially, my callback is

 def handleDownload(block, fileToWrite):
    fileToWrite.write(block)

And I need to call

ftp.retrbinary('RETR somefile', handleDownload)

And have it pass a file handle. Is there a way to do this?

Frédéric Hamidi · Accepted Answer · 2012-08-21T18:18:29.877

6

You can close over the fileToWrite variable with a lambda:

fileToWrite = open("somefile", "wb")
ftp.retrbinary("RETR somefile", lambda block: handleDownload(block, fileToWrite))

edited Aug 21 '12 at 18:18

answered Aug 21 '12 at 17:54

Frédéric Hamidi

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1

Is there any other way to download the file other than saying 'write'? I want to be able to retain the timestamp given on the FTP site. – Shyam Sunder Mar 14 '13 at 11:48

Eugene · Answer 2 · 2021-07-19T20:28:17.123

0

This code worked for me.

class File:

    cleared = False

    def __init__(self, filepath):
        self.filepath = filepath

    def write(self,block): 
        if not File.cleared:
            with open(f'{self.filepath}', 'wb') as f:
                File.cleared = True
                with open(f'{self.filepath}', 'ab') as f:
                f.write(block)
        else:
             with open(f'{self.filepath}', 'ab') as f:
                 f.write(block)

ftp.retrbinary("RETR somefile", File(filepath).write)

edited Jul 19 '21 at 20:28

answered Jul 17 '21 at 12:48

Eugene

1
1

the code should work, however You could have just made it into one function not make a whole class – Matiiss Jul 17 '21 at 17:47
one function will allow you to add only last binary block. – Eugene Jul 19 '21 at 20:29
to be fair I don't even remember commenting here, so I forgot what was my thought, so ... carry on, have a nice day – Matiiss Jul 19 '21 at 20:33

Pass a value to the ftp.retrbinary callback

2 Answers2