The **`argparse`** module provides a convenient interface to handle command-line arguments. It displays the generic usage of the program, help, and errors.

# Explanation
The **`parse_args()`** function of the `ArgumentParser` class parses arguments and the **`add_argument()`** function adds arguments to be accepted from the user.

The user often supplies a *default* value of an argument in case a value is not specified. To provide a global, parser-wide default value for arguments, the **`argument_default`** attribute is used.

# Example
The following code demonstrates how to use the `default_argument` argument.

The program provides the parser with three arguments, `r`, `x`, and `foo`. It also sets the `default_argument` to `argparse.SUPPRESS`. This means that the program will halt attribute creation if no values are provided for the arguments.

The program's output illustrates that an empty object is returned when arguments are provided to the `parse_args()` function.

import math
import argparse

# create an ArgumentParser object
parser = argparse.ArgumentParser(argument_default = argparse.SUPPRESS)
# add arguments
parser.add_argument('-r', type = int)
parser.add_argument('x', nargs = '?', )
parser.add_argument('--foo', type = int)
args = parser.parse_args('-r 2 5 --foo 5'.split())
print(args)
args = parser.parse_args(''.split())
print(args)

What is argparse argument_default in Python?

Handles command-line arguments, supplying default values globally using argument_default. If unset, suppresses attribute creation, returning an empty object.