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Diffstat (limited to 'Doc/library/optparse.rst')
| -rw-r--r-- | Doc/library/optparse.rst | 47 |
1 files changed, 22 insertions, 25 deletions
diff --git a/Doc/library/optparse.rst b/Doc/library/optparse.rst index 3d8b43c..7989d33 100644 --- a/Doc/library/optparse.rst +++ b/Doc/library/optparse.rst @@ -1625,36 +1625,33 @@ directly). Nevertheless, here's a stab at a callback for an option with variable arguments:: - def vararg_callback(option, opt_str, value, parser): - assert value is None - done = 0 - value = [] - rargs = parser.rargs - while rargs: - arg = rargs[0] - - # Stop if we hit an arg like "--foo", "-a", "-fx", "--file=f", - # etc. Note that this also stops on "-3" or "-3.0", so if - # your option takes numeric values, you will need to handle - # this. - if ((arg[:2] == "--" and len(arg) > 2) or - (arg[:1] == "-" and len(arg) > 1 and arg[1] != "-")): - break - else: - value.append(arg) - del rargs[0] - - setattr(parser.values, option.dest, value) + def vararg_callback(option, opt_str, value, parser): + assert value is None + value = [] + + def floatable(str): + try: + float(str) + return True + except ValueError: + return False + + for arg in parser.rargs: + # stop on --foo like options + if arg[:2] == "--" and len(arg) > 2: + break + # stop on -a, but not on -3 or -3.0 + if arg[:1] == "-" and len(arg) > 1 and not floatable(arg): + break + value.append(arg) + + del parser.rargs[:len(value)] + setattr(parser.values, option.dest, value)) [...] parser.add_option("-c", "--callback", dest="vararg_attr", action="callback", callback=vararg_callback) -The main weakness with this particular implementation is that negative numbers -in the arguments following ``"-c"`` will be interpreted as further options -(probably causing an error), rather than as arguments to ``"-c"``. Fixing this -is left as an exercise for the reader. - .. _optparse-extending-optparse: |