Python Argparse: Issue with optional arguments which are negative numbers

Question

I\'m having a small issue with argparse. I have an option xlim which is the xrange of a plot. I want to be able to pass numbers like <

Answer 1

If you specify the value for your option with an equals sign, argparse will not treat it as a separate option, even if it starts with -:

./blaa.py --xlim='-0.002 1e4'
# As opposed to --xlim '-0.002 1e4'

And if the value does not have spaces in it, you can drop the quotes:

./blaa.py --xlim=-0.002

See: https://www.gnu.org/software/guile/manual/html_node/Command-Line-Format.html

With this, there is no need to write your own type= parser or redefine the prefix character from - to @ as the accepted answer suggests.