I have a console script which uses ftplib as a backend to get a number of files from an ftp server. I would like to use tqdm to give the user some feedback provided they have a "verbose" switch on. This must be optional as some users might use the script without tty access.
The ftplib's retrbinary method takes a callback so it should be possible to hook tqdm in there somehow. However, I have no idea what this callback would look like.
From FTP.retrbinary:
The callback function is called for each block of data received, with a single string argument giving the data block.
So the callback could be something like:
with open(filename, 'wb') as fd:
total = ftpclient.size(filename)
with tqdm(total=total) as pbar:
def callback_(data):
l = len(data)
pbar.update(l)
fd.write(data)
ftpclient.retrbinary('RETR {}'.format(filename), callback_)
Beware: This code is untested and probably has to be adapted.
That code shouldn't work as pbar will be "closed" when the with block terminates, which occurs just before ftpclient.retrbinary(...). You need a very minor indentation mod:
with open(filename, 'wb') as fd:
total = ftpclient.size(filename)
with tqdm(total=total,
unit='B', unit_scale=True, unit_divisor=1024,
disable=not verbose) as pbar:
def cb(data):
pbar.update(len(data))
fd.write(data)
ftpclient.retrbinary('RETR {}'.format(filename), cb)
EDIT added disable flag and bytes scaling
with open(filename, 'wb') as fd:
total = ftpclient.size(filename)
with tqdm(total=total,
unit='B', unit_scale=True, unit_divisor=1024,
disable=not verbose) as pbar:
def cb(data):
pbar.update(len(data))
fd.write(data)
ftpclient.retrbinary('RETR {}'.format(filename), cb)
