Forum Archive

Simple extension to save attachment

Save.py

# coding: utf-8

import appex, os, console

def save():
    if appex.is_running_extension():
        sFp = appex.get_file_path()
        if sFp:
            console.hud_alert('Saving...')
            with open(sFp, 'rb') as f1:
                with open(os.path.basename(sFp), 'wb') as f2:
                    f2.write(f1.read())
            console.hud_alert('Saved')

if __name__ == '__main__':
    save()

See @dgelessus comment on how to replace three lines (with, with, write) above with a single call to shutil.copy().

https://forum.omz-software.com/topic/2637/is-it-possible-to-read-a-file-say-txt-file-from-other-app/3

@ccc, thanks...

• of course the opens are in binary mode so I don't think that part of the comment applies

• shorter in the source, yes, but longer and so less efficient in execution, shutil copy contains some redundant checks (eg if source and destination files are the same) and triggers a buffered copy in 16k blocks if I'm not mistaken.

I'm not sure why a copy in 16k blocks would be less efficient than reading the whole file into RAM at once... The performance difference should be minimal, and a copy in blocks is much more memory-efficient if the file is very large.

@dgelessus how many times round the write block loop for a 1MB file, 64?

The loop does little more than read a block, check whether there is data left, and write it to the output file. Heck, Unix dd uses 512-byte blocks and it gets its job done quite well. I mean, if you want to worry about that kind of optimization, run some timeits and see how the runtime difference really is. Or write your code in C and let clang optimize it. ;)

@dgelessus I think you accidentally changed your status to "away"

@Webmaster4o I always set myself as "away" (for no real reason, except that I don't want to give false impressions that I'm ready to answer when I just left the forum open).

@dgelessus or just avoid shutil copy

I added a folder picker to this to let the user choose where to save the file, but I've run into an issue. The the code runs in pythonista is comes up with a correct path, but when run in the extension it comes up with a completely dirfferent path.

Here's the path to my Documents folder generated in pythonista:

'/private/var/mobile/Containers/Shared/AppGroup/E093AECB-9BC3-4D05-A61B-E336BBA9ADF5/Documents/'

Here's the same path from the extension:

'/private/var/mobile/Containers/Data/PluginKitPlugin/CDEDAE11-0835-44A1-8AA4-F709C76285F9/Documents/'

It's exploring a totally different tree. Because of this the folder picker doesn't populate. It works if I hard code the home directory, but I'd like to know if there's a better way to do it.

The code is here.

Yes, it does look like the HOME environment variable is different in the app extension:

>>> import os
>>> os.environ["HOME"]
'/private/var/mobile/Containers/Data/PluginKitPlugin/E9D61C03-3A12-483F-916C-A77F9C49177F'

Though the cwd is still set to the normal Documents folder:

>>> os.getcwd()
'/private/var/mobile/Containers/Shared/AppGroup/4A0ADB08-4B5E-41F3-96E5-DC5CD6FC939E/Documents'

I've updated it so that is takes the result of os.getcwd and finds the main Documents folder. My way of doing it is probably considered a hack so if there's a better way feel free to let me know.

If wanting to use shutil to block copy the file... this line with copyfileobj should do it more efficiently than copy (avoiding the redundant code in copy and utilising a 512k block size instead of 16k):

#f2.write(f1.read())
shutil.copyfileobj(f1, f2, length=512*1024)