Question

I feel like this is quite delicate,

I have various folders whith projects I would like to backup into a zip/tar file, but would like to avoid backing up files such as pyc files and temporary files.

I also have a Postgres db I need to backup.

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Any tips for running this operation as a python script?

Also, would there be anyway to stop the process from hogging resources in the process?

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Help would be very much appreciated.

Answer 1

If you’re on Linux (or any other form of Unix, such as MacOSX), a simple way to reduce a process’s priority — and therefore, indirectly, its consumption of CPU if other processes want some — is the nice command. In Python (same OSs), os.nice lets your program “make itself nicer” (reduce priority &c).

For backing up a PostgreSQL DB, I recommend PostgreSQL’s own tools; for zipping up a folder except the pyc files (and temporary files — however it is you identify those), Python is quite suitable. For example:

>>> os.chdir('/tmp/az')
>>> f = open('/tmp/a.zip', 'wb')
>>> z = zipfile.ZipFile(f, 'w')
>>> for root, dirs, files in os.walk('.'):
...   for fn in files:
...     if fn.endswith('.pyc'): continue
...     fp = os.path.join(root, fn)
...     z.write(fp)
... 
>>> z.close()
>>> f.close()
>>> 

this zips all files in said subtree except those ending in .pyc (without compression — if you want compression, add a third argument zipfile.ZIP_DEFLATED to the zipfile.ZipFile call). Could hardly be easier.