[tor-bugs] #4913 [Stem]: Add stem.util.conf.Config.save()

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#4913: Add stem.util.conf.Config.save()
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 Reporter:  gsathya      |          Owner:  atagar        
     Type:  enhancement  |         Status:  needs_revision
 Priority:  normal       |      Milestone:                
Component:  Stem         |        Version:                
 Keywords:               |         Parent:                
   Points:               |   Actualpoints:                
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Changes (by atagar):

  * status:  new => needs_revision


Comment:

 > with open(path, 'w') as f:

 Ah nice, I've never run across the 'with' keyword before. I'm a little
 dubious of its general usefulness since it isn't clear what has the
 __enter__ and __exit__ methods (this is one case where a java style
 interface tag would be nice) but oh well. Files at least are the textbook
 example for using it. :)

 Minor note in case you didn't know it: 'with' wasn't introduced until
 python 2.5. That's fine though since stem aims for 2.5+ compatibility
 (otherwise some of the ternary assignment statements I've been doing will
 break too).

 Minor thing but please use another variable name, such as 'output_file'.
 Single letter variables are evil - they make the code ungrepable. For an
 amusing bit on this see 'Single Letter Variable Names' under...
 http://thc.org/root/phun/unmaintain.html

 I'm fine with using them for single line statements like...

 foo = [str(i) for i in range(5)] # becomes the list ["0", "1", "2", "3",
 "4"]

 or the classic 'i', 'j', 'k' for loop iteration ints, but for other blocks
 or anything else longer than a single line please use something longer. :)

 > for line in self._raw_contents:

 Interesting, I hadn't thought of using _raw_contents for this. This would
 generally do the trick but has a few issues...

 - if we've used the "set" method to add new config entries then those will
 be missed
 - if we later allow config values to be unset then this will have issues
 - as you mentioned commenting whitespace is lost, which is kinda common
 for these key/value configs

 While it would be nice if we had a magical function that merged the
 current config state with the user created config we loaded, there are too
 many land mines to dealing with the arbitrary user input. Lets go with the
 first implementation, though with the keys sorted.

 Thanks! -Damian

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/4913#comment:2>
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