Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #38067

Re: Floating point calculation problem

Show key headers only | View raw

On Sat, Feb 2, 2013 at 2:27 AM, Schizoid Man <schiz_man@21stcentury.com> wrote:
> I have a program that performs some calculations that runs perfectly on
> Python 2.7.3. However, when I try to execute it on Python 3.3.0 I get the
> following error:
>    numer = math.log(s)
> TypeError: a float is required
>
> The quantity s is input with the following line: s = input("Enter s:   ")
>
> To get rid of the compile error, I can cast this as a float: s =
> float(input("Enter s:   "))
<snip>
> How is
> Python dynamically typed if I need to cast (in version 3.3.0 at least) to
> get rid of the compile error?

It's *not* a compile error; it's a *runtime* error raised inside
math.log() when that function is called (with an invalid argument).
IIRC, the only compile-time error in Python is SyntaxError (and its
subclass, IndentationError).
Python is also strongly-typed, which is why, at runtime, an exception
is thrown instead of some implicit type coercion being attempted; such
coercion tends to hide genuine bugs, hence why Python avoids it.

Regards,
Chris

Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Floating point calculation problem "Schizoid Man" <schiz_man@21stcentury.com> - 2013-02-02 10:27 +0000
  Re: Floating point calculation problem Chris Angelico <rosuav@gmail.com> - 2013-02-02 21:34 +1100
    Re: Floating point calculation problem "Schizoid Man" <schiz_man@21stcentury.com> - 2013-02-02 11:14 +0000
      Re: Floating point calculation problem Chris Angelico <rosuav@gmail.com> - 2013-02-02 22:20 +1100
        Re: Floating point calculation problem "Schizoid Man" <schiz_man@21stcentury.com> - 2013-02-02 11:34 +0000
          Re: Floating point calculation problem Chris Angelico <rosuav@gmail.com> - 2013-02-02 22:38 +1100
            Re: Floating point calculation problem "Schizoid Man" <schiz_man@21stcentury.com> - 2013-02-02 11:51 +0000
              Re: Floating point calculation problem Chris Angelico <rosuav@gmail.com> - 2013-02-02 22:58 +1100
                Re: Floating point calculation problem "Schizoid Man" <schiz_man@21stcentury.com> - 2013-02-02 15:48 +0000
                Re: Floating point calculation problem "Schizoid Man" <schiz_man@21stcentury.com> - 2013-02-02 15:54 +0000
                Re: Floating point calculation problem Chris Angelico <rosuav@gmail.com> - 2013-02-03 03:00 +1100
                Re: Floating point calculation problem Michael Torrie <torriem@gmail.com> - 2013-02-02 11:19 -0700
                Re: Floating point calculation problem Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-02-03 12:25 +1100
                Re: Floating point calculation problem Dave Angel <d@davea.name> - 2013-02-02 21:20 -0500
                Re: Floating point calculation problem Michael Torrie <torriem@gmail.com> - 2013-02-02 21:22 -0700
              Re: Floating point calculation problem Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-02-02 23:11 +1100
      Re: Floating point calculation problem Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-02-02 22:45 +1100
        Re: Floating point calculation problem "Schizoid Man" <schiz_man@21stcentury.com> - 2013-02-02 11:50 +0000
  Re: Floating point calculation problem Chris Rebert <clp2@rebertia.com> - 2013-02-02 02:47 -0800
  Re: Floating point calculation problem Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-02-02 23:05 +1100

csiph-web