Use parser.epilog to display something after the generated -h text. parser = argparse.ArgumentParser( description=’My first argparse attempt’, epilog=’Example of use’) output = parser.parse_args() prints: My first argparse attempt optional arguments: -h, –help show this help message and exit Example of use
The argparse module offers a way to do this without implementing your own requiredness checks. The example below uses “subparsers” or “sub commands”. I’ve implemented a subparser for “dump” and one for “format”. import argparse parser = argparse.ArgumentParser() parser.add_argument(‘file’, help=’The file you want to act on.’) subparsers = parser.add_subparsers(dest=”subcommand”) subparsers.required = True # required since … Read more
You need to pass in the result of vars(args) instead: M(**vars(args)) The vars() function returns the namespace of the Namespace instance (its __dict__ attribute) as a dictionary. Inside M.__init__(), simply ignore the message_type key.
You are not passing in the False object. You are passing in the ‘False’ string, and that’s a string of non-zero length. Only a string of length 0 tests as false: >>> bool(”) False >>> bool(‘Any other string is True’) True >>> bool(‘False’) # this includes the string ‘False’ True Use a store_true or store_false … Read more
You can add your own type. This also allows for additional validations, for example: def coords(s): try: x, y, z = map(int, s.split(‘,’)) return x, y, z except: raise argparse.ArgumentTypeError(“Coordinates must be x,y,z”) parser.add_argument(‘–cord’, help=”Coordinate”, dest=”cord”, type=coords, nargs=3)
Since it seems like you want to run one, and only one, function depending on the arguments given, I would suggest you use a mandatory positional argument ./prog command, instead of optional arguments (./prog –command1 or ./prog –command2). so, something like this should do it: FUNCTION_MAP = {‘top20’ : my_top20_func, ‘listapps’ : my_listapps_func } parser.add_argument(‘command’, … Read more
argparse is a module designed to parse the arguments passed from the command line, so for example if you type the following at a command prompt: $ python my_programme.py –arg1=5 –arg2=7 You can use argparse to interpret the –arg1=5 –arg2=7 part. If argparse thinks the arguments are invalid, it exits, which in general is done … Read more
On Python 3.2 (and 2.7) you will get that error, but not on 3.3 and 3.4 (no response). Therefore on 3.3/3.4 you could test for parsed_args to be an empty Namespace. A more general solution is to add a method set_default_subparser() (taken from the ruamel.std.argparse package) and call that method just before parse_args(): import argparse … Read more
ArgumentParser.parse_args by default takes the arguments simply from sys.argv. So if you don’t change that behavior (by passing in something else to parse_args), you can simply print sys.argv to get all arguments passed to the Python script: import sys print(sys.argv) Alternatively, you could also just print the namespace that parse_args returns; that way you get … Read more
The type parameter to add_argument just needs to be a callable object that takes a string and returns a converted value. You can write a wrapper around float that checks its value and raises an error if it is out of range. def restricted_float(x): try: x = float(x) except ValueError: raise argparse.ArgumentTypeError(“%r not a floating-point … Read more