On 2023-01-22, Weatherby,Gerard wrote:
> Argparse is for parsing command line arguments and options.
>
> If you just want to evaluate an Python expression, use eval( )
Only use eval() if the expression is always under your control (and
you don't make mistakes when typing).
Don't use eval() on st
Hi there,
is there an easy way to evaluate a string stored in a variable as if it
were an f-string at runtime?
I.e., what I want is to be able to do this:
x = { "y": "z" }
print(f"-> {x['y']}")
This prints "-> z", as expected. But consider:
x = { "y": "z" }
s = "-> {x['y']}"
print(s.format(
Jach Feng 在 2023年1月22日 星期日上午11:11:22 [UTC+8] 的信中寫道：
> Fail on command line,
>
> e:\Works\Python>py infix2postfix.py "-4^2+5.3*abs(-2-1)/2"
> usage: infix2postfix.py [-h] [infix]
> infix2postfix.py: error: unrecognized arguments: -4^2+5.3*abs(-2-1)/2
>
> Also fail in REPL,
>
> e:\Works\Pytho
On Tue, 24 Jan 2023 at 04:56, Johannes Bauer wrote:
>
> Hi there,
>
> is there an easy way to evaluate a string stored in a variable as if it
> were an f-string at runtime?
>
> ...
>
> This is supposedly for security reasons. However, when trying to emulate
> this behavior that I wanted (and know
On 2023-01-22 at 18:19:13 -0800,
Jach Feng wrote:
> 1) Modify the sys.argv by inserting an item '--' before parsing it, ie.
> sys.argv.insert(1, '--')
> args = parser.parse_args()
Please don't do that. :-)
In my mind, sys.argv belongs to Python, not the application. Instead,
pass a newly crea
On 23Jan2023 13:46, 2qdxy4rzwzuui...@potatochowder.com
<2qdxy4rzwzuui...@potatochowder.com> wrote:
On 2023-01-22 at 18:19:13 -0800,
Jach Feng wrote:
1) Modify the sys.argv by inserting an item '--' before parsing it,
ie.
sys.argv.insert(1, '--')
args = parser.parse_args()
Please don't do th
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 --
On 2023-01-22 at 18:19:13 -0800,
Jach Feng wrote:
1) Modify the sys.argv by inserting an item '--' before parsing it, ie.
sys.argv.insert(1, '--')
args = parser.parse_args()
If you do that, you'll never be able to have any actual options, so
using argparse seems like overkill. Just pull the ar
2qdxy4rz...@potatochowder.com 在 2023年1月24日 星期二凌晨2:47:12 [UTC+8] 的信中寫道：
> On 2023-01-22 at 18:19:13 -0800,
> Jach Feng wrote:
>
> > 1) Modify the sys.argv by inserting an item '--' before parsing it, ie.
> > sys.argv.insert(1, '--')
> > args = parser.parse_args()
> Please don't do that. :-)
>
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 ar
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, _explici
Greg Ewing 在 2023年1月24日 星期二清晨7:33:43 [UTC+8] 的信中寫道：
> >> On 2023-01-22 at 18:19:13 -0800,
> >> Jach Feng wrote:
> >>> 1) Modify the sys.argv by inserting an item '--' before parsing it, ie.
> >>> sys.argv.insert(1, '--')
> >>> args = parser.parse_args()
> If you do that, you'll never be able t
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 o
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