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Groups > comp.lang.python > #87421

Re: Odd ValueError using float

From emile <emile@fenx.com>
Subject Re: Odd ValueError using float
Date 2015-03-14 08:28 -0700
References <mailman.336.1426284641.21433.python-list@python.org> <877fuk71fz.fsf@nightsong.com> <CAPTjJmoxL0ux3mHAd8UCZmdbTHe_Yz5i9Y8XrzJ7NAuy8WZ4sA@mail.gmail.com>
Newsgroups comp.lang.python
Message-ID <mailman.355.1426346915.21433.python-list@python.org> (permalink)

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On 03/13/2015 08:09 PM, Chris Angelico wrote:
> On Sat, Mar 14, 2015 at 1:33 PM, Paul Rubin <no.email@nospam.invalid> wrote:
>> emile <emile@fenx.com> writes:
>>> *** NameError: name 'val' is not defined
>>> (Pdb) l
>>> 139         try:
>>> 140             val = round(float(decval),1)
>>> 141         except:
>>> 142             import pdb; pdb.set_trace()
>>
>> If 'float' or 'round' throw an exception, the assignment to 'val' never
>> happens, so 'val' is undefined.  Try examining the value of 'decval' in
>> the debugger to see what is making the conversion fail.
>
> That's exactly what the OP did :) Trouble is, it didn't help, because
> it sure looked as if decval was the string '4'. My best guess was -
> and is - that it's not just a string. We're looking at an SQL
> interface routine here, so it may be that there's a string subclass
> that length-limits itself, on the assumption that it's going into a
> fixed-length database field.

It ran almost to completion before generating the error again --

(Pdb) decval
'4'
(Pdb) type(decval)
<type 'str'>
(Pdb) len(decval)
1
(Pdb) int(decval)
*** ValueError: invalid literal for int() with base 10: '41.700000000000003'

So there's still something amiss.

Emile

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Thread

Odd ValueError using float emile <emile@fenx.com> - 2015-03-13 15:10 -0700
  Re: Odd ValueError using float Paul Rubin <no.email@nospam.invalid> - 2015-03-13 19:33 -0700
    Re: Odd ValueError using float Chris Angelico <rosuav@gmail.com> - 2015-03-14 14:09 +1100
    Re: Odd ValueError using float emile <emile@fenx.com> - 2015-03-14 08:28 -0700
    Re: Odd ValueError using float Chris Angelico <rosuav@gmail.com> - 2015-03-15 02:52 +1100
    Re: Odd ValueError using float Peter Otten <__peter__@web.de> - 2015-03-14 17:08 +0100
    Re: Odd ValueError using float emile <emile@fenx.com> - 2015-03-14 10:08 -0700
    Re: Odd ValueError using float emile <emile@fenx.com> - 2015-03-14 10:17 -0700
    Re: Odd ValueError using float Peter Otten <__peter__@web.de> - 2015-03-14 19:24 +0100
    Re: Odd ValueError using float emile <emile@fenx.com> - 2015-03-14 13:01 -0700
    Re: Odd ValueError using float Peter Otten <__peter__@web.de> - 2015-03-15 15:01 +0100
    Re: Odd ValueError using float emile <emile@fenx.com> - 2015-03-17 13:48 -0700

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