Suppose I have a file hosted on GCS on a Python AppEngine project. unfortunately, this file structure is something like:
outer.zip/
- inner.zip/
- vid_file
- png_file
the problem is that the two files inside inner.zip do not have the .mp4 extension on the file, and it's causing all sorts of troubles. How do i rename the files so that it appears like:
outer.zip/
- inner.zip/
- vid_file.mp4
- png_file.png
so that the files inside inner.zip have their extensions?
I keep running into all sorts of limitations since gcs doesn't allow file renaming, unarchiving...etc.
the files aren't terribly large.
P.S. i'm not very familiar with Python, so any code examples would be great appreciated, thanks!
There is absolutely no way to perform any alteration to GCS objects -- full stop. They are exactly the bunch of bytes you decided at their birth (uninterpreted by GCS itself) and thus they will stay.
The best you can do is create a new object which is almost like the original except it fixes little errors and oopses you did when creating the original. Then you can overwrite (i.e completely replace) the original with the new, improved version.
Hopefully it's a one-off terrible mistake you made just once and now want to fix so it's not worth writing a program for that. Just download that GCS object, use normal tools to unzip it and unzip any further zipfiles it may contain, do the fixes on the filesystem with your favorite local filesystem tools, zip things up again, upload/rewrite the final zip to your desired new GCS object -- phew, you're done.
Alex is right that objects are immutable, i.e., no editing in-place. The only way to accomplish what you're talking about would be to download the current file, unzip it, update the new files, re-zip the files into the same-named file, and upload to GCS. GCS object overwrites are transactional, so the old content will be visible until the instant the upload completes. Doing it this way is obviously not very network efficient but at least it wouldn't leave periods of time when the object is invisible (as deleting and re-uploading would).
"Import zipfile" and you can unzip the file once it's downloaded into gcs storage.
I have code doing exactly this on a nightly basis from a cron job.
Ive never tried creating a zip file with GAE but the docs say you can do it.
https://docs.python.org/2/library/zipfile.html
Related
I am relatively new to web development and very new to using Web2py. The application I am currently working on is intended to take in a CSV upload from a user, then generate a PDF file based on the contents of the CSV, then allow the user to download that PDF. As part of this process I need to generate and access several intermediate files that are specific to each individual user (these files would be images, other pdfs, and some text files). I don't need to store these files in a database since they can be deleted after the session ends, but I am not sure the best way or place to store these files and keep them separate based on each session. I thought that maybe the subfolders in the sessions folder would make sense, but I do not know how to dynamically get the path to the correct folder for the current session. Any suggestions pointing me in the right direction are appreciated!
I was having this error "TypeError: expected string or Unicode object, NoneType found" and I had to store just a link in the session to the uploaded document in the db or maybe the upload folder in your case. I would store it to upload to proceed normally, and then clear out the values and the file if not 'approved'?
If the information is not confidential in similar circumstances, I directly write the temporary files under /tmp.
I want to use s3fs based on fsspec to access files on S3. Mainly because of 2 neat features:
local caching of files to disk with checking if files change, i.e. a file gets redownloaded if the local and remote file differ
file version id support for versioned S3 buckets, i.e. the ability to open different versions of the same remote file based on their version id
I don't need this for high frequency use and the files don't change often. It is mainly for using unit/integration test data stored on S3, which changes only if tests and related test data get updated (versions!).
I got both of the above working separately just fine, but it seems I can't get the combination of the two working. That is, I want to be able to cache different versions of the same file locally. It seems that as soon as you use a filecache, the version id disambiguation is lost.
fs = fsspec.filesystem("filecache", target_protocol='s3', cache_storage='/tmp/aws', check_files=True, version_aware=True)
with fs.open("s3://my_bucket/my_file.txt", "r", version_id=version_id) as f:
text = f.read()
No matter what version_id is, I always get the most recent file from S3, which is also the one that gets cached locally.
What I expect is that I always get the correct file version and the local cache either keeps separate files for each version (preferred) or just updates the local file whenever I request a version different from the cached one.
Is there a way I can achieve this with the current state of the libraries or is this currently not possible? I am using s3fs==fsspec==2022.3.0.
After checking with the developers this combination seems not to be possible with the current state of the libraries, since the hash of the target file is based on the filepath alone, disregarding any other kwargs such as version_id.
I tried with SASpy but it's not working. I am able to open the SAS .egp file but not able to run the multiple scripts within in sequence.
import os, sys, subprocess
def OpenProject(sas_exe, egp_path):
sasExe = sas_exe
sasEGpath = egp_path
subprocess.call([sasExe, sasEGpath])
sas_exe = path\path\
egp_path = path\path\path\
OpenProject(sas_exe, egp_path)
This depends a bit on exactly what the workflow is. A few side notes, then the full solution.
First: EGP is not really intended to store production processes, in my opinion. EGP should really be used for development, then production is done with .sas (text) files. EGP can directly store the nodes as .sas files; ask a new question about that if you want to know more, but it's pretty easy to figure out. Best practice is to have EGP save the code modules as .sas files, then run those - SASPy will easily do that for you.
Second: If you use SAS's built-in Git connectivity, then you can do this a bit more easily I suspect. Consider doing that if you already use Git for your other processes. Again, then you end up with a .sas file, and can directly run that via SASPy.
So: how can you do this in Python, with the assumption you do have to use the .egp itself, without too many different moving parts? The key here is the .egp format. EGP is a container file, which is actually a .zip format container that has in it, among other things, all of the SAS code you want to run, as text. Text in xml format, but still, text.
You can write a python program that opens the .egp as a .zip file, using the zipfile library, and then use xml.etree.ElementTree to parse the project.xml file inside that project. Exactly what you do from there depends on your particular details, and is well out of scope for a Stack Overflow answer, but if you do better visually you can simply rename the .egp to .zip and then open in unzip program of your choice, then browse project.xml in your text editor, and find the nodes and code related to those nodes.
You can then extract the .sas code as text, and submit it directly via SASPy, or extract it to a .sas file and then submit that however you prefer (SASPy or something else).
I do something similar to this for a project - I don't actually run code from it, I'm just parsing it to verify that the correct programs were synced from the EGP to production - but it would be trivial to actually submit the code from what I've written, which is about 50 lines of code total. I may write a SGF paper this year or next year on this topic, in which case I'll try and remember to submit it here - or you can head over to my github page and see if it's there (in the future!).
I have to python files that create and read text from a .txt file, in order for them to work they need to know the info inside of the .txt file.
In heroku I have a scheduler that runs one file, then the other. The big problem is that the files are reset every time to their state from the original repo. How can I get around this?
Heroku does not offer a persistent file system. You will need to store them in another service (like S3), or depending on what the contents of your files are, redesign to write and read from a database instead.
Is there a way to read the contents of a static data directory or interact with that data in any way from within the code of an application?
Edit: Please excuse me if it wasn't clear at first, I mean getting a list of the files in that directory, not reading the data in them.
No. Files marked as static in app.yaml are not available to your application; they're served from separate servers.
If you just need to list them, you could build a list as part of your deploy process. If you need to actually read them, you'll need to include a second copy in your application directory (although the "copy" can be just a symlink; appcfg.py will follow symlinks and upload them.)
You can just open them (only read only).