Re: bool and int
Will all of you please stop sending me emails Sent from my iPhone > On Jan 24, 2023, at 2:59 PM, rbowman wrote: > > On Mon, 23 Jan 2023 23:22:00 -0500, Dino wrote: > >> $ python Python 3.8.10 (default, Mar 15 2022, 12:22:08) >> [GCC 9.4.0] on linux Type "help", "copyright", "credits" or "license" >> for more information. > b = True isinstance(b,bool) >> True > isinstance(b,int) >> True > > >> WTF! > > b = True isinstance(b, bool) > True isinstance(b, int) > True c = b + 10 print(c) > 11 b = False c = b + 10 print(c) > 10 > > > bool is a subtype of integer. I never dug that deep into Python's guts but > I assume it goes back to boolean being an afterthought in C. Some people > fancy it up with #defines but I always use int. 0 is false, anything else > is true. > > C# is pickier, which I guess is a good thing. > -- > https://mail.python.org/mailman/listinfo/python-list -- https://mail.python.org/mailman/listinfo/python-list
Re: How to make argparse accept "-4^2+5.3*abs(-2-1)/2" string argument?
Can you stop please Sent from Yahoo Mail for iPhone On Tuesday, January 24, 2023, 10:12 AM, Thomas Passin wrote: On 1/23/2023 9:12 PM, Chris Angelico wrote: > On Tue, 24 Jan 2023 at 13:09, Jach Feng wrote: >> >> Chris Angelico 在 2023年1月24日 星期二清晨5:00:27 [UTC+8] 的信中寫道： >>> On Tue, 24 Jan 2023 at 07:47, Cameron Simpson wrote: But for Jach Feng: the "--" is really expected as something the user does when they invoke your programme, _explicitly_ saying that what follows from here is not an argument. So the user is expected to type: your_script -x -y -- "-4^2+5.3*abs(-2-1)/2" where there are -x and -y options, then end of options, then an argument, which would look like an option if there wasn't the "--" argument. >>> And if you DON'T expect the user to enter the "--", then why use >>> argparse? You can just check argv directly to get your arguments. >>> >>> This entire thread is a massive "how can I use X to do Y?" problem. >>> >>> ChrisA >> The '--' requirement makes its usage less instinctive, and handling argv >> directly makes me loss the benefit of using '-h':-) > > if "-h" in sys.argv: usage() > else: do_stuff_with(sys.argv[1:]) > > What is argparse really doing for you? I second this. "if '-h' in sys.argv:" is usually what I do. Alternatively, you could use "--arg=" syntax and place your string "-4^2+5.3*abs(-2-1)/2" its right-hand side": infix2postfix [options] "--infix=-4^2+5.3*abs(-2-1)/2" This shouldn't be too hard for a user to work with. You could scan the argument list for the presence of "--infix=" and display the help message if it isn't there. -- https://mail.python.org/mailman/listinfo/python-list -- https://mail.python.org/mailman/listinfo/python-list
Re: How to make argparse accept "-4^2+5.3*abs(-2-1)/2" string argument?
Stop please Sent from Yahoo Mail for iPhone On Tuesday, January 24, 2023, 1:05 AM, Cameron Simpson wrote: On 23Jan2023 17:58, Jach Feng wrote: parser.parse_args(['--', 'infix2postfix.py', '-4.3+5']) >usage: [-h] infix >: error: unrecognized arguments: -4.3+5 This error doesn't look like "-4.3+5 looks like an option" but instead "we don't expect any arguments after "infix". Not personally a fan of argparse myself, but then I have my own elaborate command line framework which generally uses getopt for the option stuff. Cheers, Cameron Simpson -- https://mail.python.org/mailman/listinfo/python-list -- https://mail.python.org/mailman/listinfo/python-list
