This issue tracker has been migrated to GitHub, and is currently read-only.
For more information, see the GitHub FAQs in the Python's Developer Guide.

Author jnespolo
Recipients jnespolo
Date 2014-10-19.18:10:15
SpamBayes Score -1.0
Marked as misclassified Yes
Message-id <>
Argparse fails to recognise negative numbers in scientific notation as valid numbers.

Suppose the program has this option.
    par.add_argument('-a', type=float)

then './ -a -1e5' will fail, as well as -1.0e-4, -.5E+4 and variations thereof.
Furthermore, at the current state, it seems that argparse does not recognize -1. as a valid float either.

I tried to hack myself, and I believe the patch attached should fix this issue. The base version of is the one from Python 3.4.2 as found in Debian Sid.

The modified regular expression seemed to behave correctly in all test cases I could come up with.
Date User Action Args
2014-10-19 18:10:15jnespolosetrecipients: + jnespolo
2014-10-19 18:10:15jnespolosetmessageid: <>
2014-10-19 18:10:15jnespololinkissue22672 messages
2014-10-19 18:10:15jnespolocreate