Thomas Lee <tom@vector-seven.com> wrote:

Hi folks,

Would anybody support the idea of read-only dict-like behaviour of "options" for the following code:

====

from optparse import OptionParser parser = OptionParser() parser.add_option("--host", dest="host" default="localhost") parser.add_option("--port", dest="port", default=1234) parser.add_option("--path", dest="path", default="/tmp") options, args = parser.parse_args()

====

I presume you know that dest is redundant there? I ask because you wanted to avoid retyping the option names later :)

As it is, you have to "know" what possible attributes are present on the options (effectively the set of "dest" attributes) -- I often implement something like the following because recently I've had to use command line options in a bunch of format strings:

def make_options_dict(options): known_options = ("host", "port", "path") return dict(zip(known_options, [getattr(options, attr) for attr in known_options]))

I don't mind having to do this, but having to hard code the options in there feels a bit nasty. Just as useful for my particular use case (i.e passing the options "dict" to a format string) would be something along the lines of options.todict() or dict(options). Even a way to know the set of "dest" attributes that are defined on "options" would be cleaner. e.g.

Well, given the implementation of optparse, you could do: options.__dict__.items() But exposing the full dictionary interface on options strikes me as a reasonable idea. I don't see any particular reason to make it read-only, either. (NB: The Values class has some...interesting...methods that I wasn't aware of that look somewhat intriguing. And they aren't read-only.)

options_dict = dict(zip(options.all(), [getattr(options, attr) for attr in options.all()]))

Where options.all() returns all the option "dest" attribute names.

Or something to that effect.

Any thoughts?

I don't see any reason not to just duck type the options object as dictionary-like and use the normal dictionary method names to access the information you want. Off the cuff it seems like a good idea to expose an interface to this information. Hmm. Then I could do globals().update(options.items()), which would simplify some of my code :) (Whether or not that is a good idea is a different question!) -- R. David Murray http://www.bitdance.com

Thomas Lee <tom@vector-seven.com> wrote:

Hi folks,

Would anybody support the idea of read-only dict-like behaviour of "options" for the following code:

====

from optparse import OptionParser parser = OptionParser() parser.add_option("--host", dest="host" default="localhost") parser.add_option("--port", dest="port", default=1234) parser.add_option("--path", dest="path", default="/tmp") options, args = parser.parse_args()

====

I presume you know that dest is redundant there? I ask because you wanted to avoid retyping the option names later :)

As it is, you have to "know" what possible attributes are present on the options (effectively the set of "dest" attributes) -- I often implement something like the following because recently I've had to use command line options in a bunch of format strings:

def make_options_dict(options): known_options = ("host", "port", "path") return dict(zip(known_options, [getattr(options, attr) for attr in known_options]))

I don't mind having to do this, but having to hard code the options in there feels a bit nasty. Just as useful for my particular use case (i.e passing the options "dict" to a format string) would be something along the lines of options.todict() or dict(options). Even a way to know the set of "dest" attributes that are defined on "options" would be cleaner. e.g.

Well, given the implementation of optparse, you could do: options.__dict__.items() But exposing the full dictionary interface on options strikes me as a reasonable idea. I don't see any particular reason to make it read-only, either. (NB: The Values class has some...interesting...methods that I wasn't aware of that look somewhat intriguing. And they aren't read-only.)

options_dict = dict(zip(options.all(), [getattr(options, attr) for attr in options.all()]))

Where options.all() returns all the option "dest" attribute names.

Or something to that effect.

Any thoughts?

I don't see any reason not to just duck type the options object as dictionary-like and use the normal dictionary method names to access the information you want. Off the cuff it seems like a good idea to expose an interface to this information. Hmm. Then I could do globals().update(options.items()), which would simplify some of my code :) (Whether or not that is a good idea is a different question!) -- R. David Murray http://www.bitdance.com