[Tutor] Nested for loops, possibly?

[DaveA]

On February 5, 2015 12:33:56 PM EST, Bob Williams <linux at barrowhillfarm.org.uk> wrote:
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>On 05/02/15 14:59, DaveA wrote:
>> 
>> 

Sorry my last message was in html, and indentation trashed .  I just installed k9 on my tablet and hadn't yet found the setting for text-only. Let m know if this one is also messed up.


>> 
>> I'd put these Values into a class, and make a list of instances. If
>> you're not yet comfortable with that, it would also be possible to
>> make a list per "paragraph", and use zip to combine them, as
>> already suggested.
>> 
>I also felt that there was something wrong with that long list of
>variables. However, I'm new to classes, so I'll need to do some
>background reading. Thank you for the pointer.

You don't need much class understanding at all for this.  Something like:

class Job:
    def __init__(self, retain, srcpath, suffix, syncpath, snappath, ...):
        self.retain = retain = datetime.timedelta  (days = retain)
        self.srcpath = os.path.join (srcpath, suffix)
         self.syncpath = os.path.join  (....

Notice that in the above method,  the object is called self, while in the loop in main it'll be called job, or whatever you use as a loop variable. 

>
>> The class would hold retain, srcpath, syncpath, snappath, etc. And
>> your list would have 7 instances of that class currently,
>> corresponding to your doc, pic, misc, ...
>> 
>> That list would be THE global, replacing these 35 or so. It would
>> be populated something like:
>> 
>> def initialize (worklist=[]): worklist . append  (Job (90,
>> src_path, "Documents", "documents", "docsnaps") worklist .append
>> (Job (90, src_path,  "Pictures", ... .... return worklist

(Reformatting )

def initialize (worklist=[]): 
    worklist . append  (Job (90, src_path, "Documents", "documents", "docsnaps") 
    worklist .append(Job (90, src_path,  "Pictures", ... 
     ....
    return worklist

>> 
>> Now all the joins and globs are done in the Job initializer, just
>> once.
>> 



>>> 
>>> def main(): print("Backing up ", src_path, "/Documents\n",
>>> sep='') do_sync(doc_srcpath, doc_syncpath) 
>>> create_snaps(doc_syncpath, doc_snappath) print("Documents backup
>>> completed.") expire_snaps(doc_snaplist, today, doc_retain)
>> 
>> At this point main becomes something like
>> 
def main ():
    jobs = initialize ()
    for job in jobs: 
        do_sync (job.srcpath, job.syncpath) 
        create_snaps (job.syncpath,  job.snappath) 
        expire_snaps (job.snaplist, ...





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