14.3.3.6 Standard option types

optparse has six built-in option types: string, int, long, choice, float and complex. If you need to add new option types, see section 14.3.5, Extending optparse.

Arguments to string options are not checked or converted in any way: the text on the command line is stored in the destination (or passed to the callback) as-is.

Integer arguments (type int or long) are parsed as follows:

• if the number starts with 0x, it is parsed as a hexadecimal number

• if the number starts with 0, it is parsed as an octal number

• if the number starts with 0b, is is parsed as a binary number

• otherwise, the number is parsed as a decimal number

The conversion is done by calling either int() or long() with the appropriate base (2, 8, 10, or 16). If this fails, so will optparse, although with a more useful error message.

float and complex option arguments are converted directly with float() and complex(), with similar error-handling.

choice options are a subtype of string options. The choices option attribute (a sequence of strings) defines the set of allowed option arguments. optparse.check_choice() compares user-supplied option arguments against this master list and raises OptionValueError if an invalid string is given.

See About this document... for information on suggesting changes.