Iterating command switches from a data file - have a working solution but it seems inefficient

[John Machin]

On 13/04/2006 12:26 PM, James Stroud wrote:
> John Machin wrote:
>> On 13/04/2006 11:23 AM, James Stroud wrote:
> 
>>> opt_map = {'m': 'Queue Manager',  's': 'Server',  'p': 'Port',
>>>            'o': 'Object',         'k': 'Key',     't': 'To',
>>>            'c': 'Check',          'd': 'Report',  'q': 'Display}
>>>
>>
>> 'Queue Manager' is not suitable for later use as an attribute name.
> 
> Who said anything about attribute names? I did it this way to show the 
> OP that not every value has to be "select variables which would 
> eventually be included in a class object".

Sorry, I don't understand that sentence.

> Using a dict would be far 
> more attractive than a bunch of "setattr" & "getattr"s later.

Who said anything about a bunch of *attrs later?

Instead of
	settings[opt_map[flag]] = option
you'd have
	setattr(anobj, opt_map[flag], option)
with the __init__ for the class setting up the default values.
And no getattrs, you'd use the names like qmgr and port as per the OP: 
anobj.qmgr, anobj.port, etc ...

> 
>>> afile = open("filename")
>>>
>>> settings = {}
>>> for aline in afile:
>>>   splitline = aline.split()
>>>   flags, options = splitline[::2], splitline[1::2]
>>>   flags = [f[1] for f in flags]  # get rid of pesky "-"s
>>
>>
>> Actually that's getting rid of the first character irrespective of 
>> whether it's "-" or not -- except when there's only one character in 
>> which case it will die in a hole.
> 
> Who said the "-" was optional?

Nobody. Who said the user data was going to be syntactically correct?

> 
>>>   for flag, option in zip(flags, options):
>>>     settings[opt_map(flag)] = option
>>>     print "%s = %s" % (opt_map(flag), option)
>>
>>
>> opt_map is a dict; should be opt_map[flag] in above two lines
> 
> Typos.
> 
>>> afile.close()
>>>
>>
>> Like Peter said, use optparse -- it handles the no-argument flags, has 
>> error detection, defaults, can be told the type of the flag, already 
>> returns the goodies as attributes of an object, ...
> 
> Peter's post was up when I responded, but it does not give the OP any 
> ideas about how to write better python code. 

Yes it does. It gives the OP the idea that if there's a Python standard 
module that does the job, the best Python code that the OP could write 
would be calls to that module.

> Note the 4 page if...elif 
> construct.

I did. I read *all* of it.

>  optparse might be logical for vet pythonistas, but if someone 
> is writing code like to OP, it might be better to give him some coding 
> hints at the expense of sophistication.

The "sophistication" of optparse appears to match what the OP appears to 
want to do; IMO preferable to the sophistry of something like

flags, options = splitline[::2], splitline[1::2]

which is sure to cause the OP some headscratching and needs to be thrown 
away immediately he starts to consider (a) variable number of parameters 
(b) error detection.