Inheritance diagram of OptionParser

class mvpa2.misc.cmdline.OptionParser(usage=None, option_list=None, option_class=<class optparse.Option>, version=None, conflict_handler='error', description=None, formatter=None, add_help_option=True, prog=None, epilog=None)
Class attributes:
standard_option_list : [Option]
list of standard options that will be accepted by all instances of this parser class (intended to be overridden by subclasses).
Instance attributes:
usage : string
a usage string for your program. Before it is displayed to the user, “%prog” will be expanded to the name of your program (self.prog or os.path.basename(sys.argv[0])).
prog : string
the name of the current program (to override os.path.basename(sys.argv[0])).
description : string
A paragraph of text giving a brief overview of your program. optparse reformats this paragraph to fit the current terminal width and prints it when the user requests help (after usage, but before the list of options).
epilog : string
paragraph of help text to print after option help
option_groups : [OptionGroup]
list of option groups in this parser (option groups are irrelevant for parsing the command-line, but very useful for generating help)
allow_interspersed_args : bool = true

if true, positional arguments may be interspersed with options. Assuming -a and -b each take a single argument, the command-line

-ablah foo bar -bboo baz
will be interpreted the same as
-ablah -bboo – foo bar baz
If this flag were false, that command line would be interpreted as
-ablah – foo bar -bboo baz

– ie. we stop processing options as soon as we see the first non-option argument. (This is the tradition followed by Python’s getopt module, Perl’s Getopt::Std, and other argument- parsing libraries, but it is generally annoying to users.)

process_default_values : bool = true
if true, option default values are processed similarly to option values from the command line: that is, they are passed to the type-checking function for the option’s type (as long as the default value is a string). (This really only matters if you have defined custom types; see SF bug #955889.) Set it to false to restore the behaviour of Optik 1.4.1 and earlier.
rargs : [string]
the argument list currently being parsed. Only set when parse_args() is active, and continually trimmed down as we consume arguments. Mainly there for the benefit of callback options.
largs : [string]
the list of leftover arguments that we have skipped while parsing options. If allow_interspersed_args is false, this list is always empty.
values : Values
the set of option values currently being accumulated. Only set when parse_args() is active. Also mainly for callbacks.

Because of the ‘rargs’, ‘largs’, and ‘values’ attributes, OptionParser is not thread-safe. If, for some perverse reason, you need to parse command-line arguments simultaneously in different threads, use different OptionParser instances.


add_option_group(*args, **kwargs)
check_values(values : Values, args : [string]) -> (values : Values, args : [string])

-> (values : Values, args : [string])

Check that the supplied option values and leftover arguments are valid. Returns the option values and leftover arguments (possibly adjusted, possibly completely new – whatever you like). Default implementation just returns the passed-in values; subclasses may override as desired.


Declare that you are done with this OptionParser. This cleans up reference cycles so the OptionParser (and all objects referenced by it) can be garbage-collected promptly. After calling destroy(), the OptionParser is unusable.


Set parsing to stop on the first non-option. Use this if you have a command processor which runs another command that has options of its own and you want to make sure these options don’t get confused.


Set parsing to not stop on the first non-option, allowing interspersing switches with command arguments. This is the default behavior. See also disable_interspersed_args() and the class documentation description of the attribute allow_interspersed_args.

error(msg : string)

Print a usage message incorporating ‘msg’ to stderr and exit. If you override this in a subclass, it should not return – it should either exit or raise an exception.

exit(status=0, msg=None)
parse_args(args : [string] = sys.argv[1:], values : Values = None) -> (values : Values, args : [string])

Parse the command-line options found in ‘args’ (default: sys.argv[1:]). Any errors result in a call to ‘error()’, which by default prints the usage message to stderr and calls sys.exit() with an error message. On success returns a pair (values, args) where ‘values’ is an Values instance (with all your option values) and ‘args’ is the list of arguments left over after parsing options.

print_help(file : file = stdout)

Print an extended help message, listing all options and any help text provided with them, to ‘file’ (default stdout).

print_usage(file : file = stdout)

Print the usage message for the current program (self.usage) to ‘file’ (default stdout). Any occurrence of the string “%prog” in self.usage is replaced with the name of the current program (basename of sys.argv[0]). Does nothing if self.usage is empty or not defined.

print_version(file : file = stdout)

Print the version message for this program (self.version) to ‘file’ (default stdout). As with print_usage(), any occurrence of “%prog” in self.version is replaced by the current program’s name. Does nothing if self.version is empty or undefined.

set_default(dest, value)
standard_option_list = []