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Python Library Reference |  |
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Python Library Reference | |
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optparse is a more convenient, flexible, and powerful library for
parsing command-line options than getopt. optparse uses a more
declarative style of command-line parsing: you create an instance of
OptionParser, populate it with options, and parse the command line.
optparse allows users to specify options in the conventional GNU/POSIX
syntax, and additionally generates usage and help messages for you.
Here's an example of using optparse in a simple script:
from optparse import OptionParser
[...]
parser = OptionParser()
parser.add_option("-f", "--file", dest="filename",
help="write report to FILE", metavar="FILE")
parser.add_option("-q", "--quiet",
action="store_false", dest="verbose", default=True,
help="don't print status messages to stdout")
(options, args) = parser.parse_args()
With these few lines of code, users of your script can now do the ``usual thing'' on the command-line, for example:
<yourscript> --file=outfile -q
As it parses the command line, optparse sets attributes of the
options object returned by parse_args() based on user-supplied
command-line values. When parse_args() returns from parsing this
command line, options.filename will be "outfile" and
options.verbose will be False. optparse supports both long
and short options, allows short options to be merged together, and
allows options to be associated with their arguments in a variety of
ways. Thus, the following command lines are all equivalent to the above
example:
<yourscript> -f outfile --quiet <yourscript> --quiet --file outfile <yourscript> -q -foutfile <yourscript> -qfoutfile
Additionally, users can run one of
<yourscript> -h <yourscript> --help
and optparse will print out a brief summary of your script's
options:
usage: <yourscript> [options] options: -h, --help show this help message and exit -f FILE, --file=FILE write report to FILE -q, --quiet don't print status messages to stdout
where the value of yourscript is determined at runtime (normally
from sys.argv[0]).
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Python Library Reference | |
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