Neal Becker wrote:
Robert Kern wrote:
On 3/15/11 9:54 AM, Neal Becker wrote:
Is there any way to tell if an arg value was defaulted vs. set on command
line?
No. If you need to determine that, don't set a default value in the
add_argument() method. Then just check for None and replace it with the
default value and do whatever other processing for the case where the user
does not specify that argument.
parser.add_argument('-f', '--foo', help="the foo argument [default: bar]")
args = parser.parse_args()
if args.foo is None:
args.foo = 'bar'
print 'I'm warning you that you did not specify a --foo argument.'
print 'Using default=bar.'
Not a completely silly use case, actually. What I need here is a combined
command line / config file parser.
Here is my current idea:
-----------------------------
parser = OptionParser()
parser.add_option ('--opt1', default=default1)
(opt,args) = parser.parse_args()
import json, sys
for arg in args:
print 'arg:', arg
d = json.load(open (arg, 'r'))
parser.set_defaults (**d)
(opt,args) = parser.parse_args()
-----------------------
parse_args() is called 2 times. First time is just to find the non-option args,
which are assumed to be the name(s) of config file(s) to read. This is used to
set_defaults. Then run parse_args() again.
Is that what you want ?
"user CLI > json defaults > script default"
If so, your idea seems good.
Otherwise
"--opt1" in sys.argv
would tell you if an option has been specified through the CLI. But it
seems to me anti-pattern. You should not need to parse the CLI, that's
the purpose of using optparse.
JM
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