"""\
:Author: M. Simionato
:Date: April 2004
:Title: A much simplified interface to optparse.
You should use optionparse in your scripts as follows.
First, write a module level docstring containing something like this
(this is just an example):
'''usage: %prog files [options]
-d, --delete: delete all files
-e, --erase = ERASE: erase the given file'''
Then write a main program of this kind:
# sketch of a script to delete files
if __name__=='__main__':
import optionparse
option,args=optionparse.parse(__doc__)
if not args and not option: optionparse.exit()
elif option.delete: print "Delete all files"
elif option.erase: print "Delete the given file"
Notice that ``optionparse`` parses the docstring by looking at the
characters ",", ":", "=", "\\n", so be careful in using them. If
the docstring is not correctly formatted you will get a SyntaxError
or worse, the script will not work as expected.
"""
import optparse, re, sys
USAGE = re.compile(r'(?s)\s*usage: (.*?)(\n[ \t]*\n|$)')
def nonzero(self): # will become the nonzero method of optparse.Values
"True if options were given"
for v in self.__dict__.itervalues():
if v is not None: return True
return False
optparse.Values.__nonzero__ = nonzero # dynamically fix optparse.Values
class ParsingError(Exception): pass
optionstring=""
def exit(msg=""):
raise SystemExit(msg or optionstring.replace("%prog",sys.argv[0]))
def parse(docstring, arglist=None):
global optionstring
optionstring = docstring
match = USAGE.search(optionstring)
if not match: raise ParsingError("Cannot find the option string")
optlines = match.group(1).splitlines()
try:
p = optparse.OptionParser(optlines[0])
for line in optlines[1:]:
opt, help=line.split(':')[:2]
short,long=opt.split(',')[:2]
if '=' in opt:
action='store'
long=long.split('=')[0]
else:
action='store_true'
p.add_option(short.strip(),long.strip(),
action = action, help = help.strip())
except (IndexError,ValueError):
raise ParsingError("Cannot parse the option string correctly")
return p.parse_args(arglist)
