python 2.2 string conversion ?

Re: python 2.2 string conversion ?

On Thu, 24 Jul 2003 05:31:17 GMT, "ken" <kericks272@ear thlink.net> wrote:
[color=blue]
>I've been looking for a solution to a string to long conversion problem that
>I've run into
>[color=green][color=darkred]
>>>> x = 'e10ea210'
>>>> print x[/color][/color]
>e10ea210[color=green][color=darkred]
>>>> y=long(x)[/color][/color]
>Traceback (most recent call last):
> File "<pyshell#2 >", line 1, in ?
> y=long(x)
>ValueError: invalid literal for long(): e10ea210[color=green][color=darkred]
>>>> x='0xe10ea210'
>>>> print x[/color][/color]
>0xe10ea210[color=green][color=darkred]
>>>> y=long(x)[/color][/color]
>Traceback (most recent call last):
> File "<pyshell#5 >", line 1, in ?
> y=long(x)
>ValueError: invalid literal for long(): 0xe10ea210[color=green][color=darkred]
>>>> x="e10ea210"
>>>> y=long(x)[/color][/color]
>Traceback (most recent call last):
> File "<pyshell#7 >", line 1, in ?
> y=long(x)
>ValueError: invalid literal for long(): e10ea210[color=green][color=darkred]
>>>> x="0xe10ea210 "
>>>> y=long(x)[/color][/color]
>Traceback (most recent call last):
> File "<pyshell#9 >", line 1, in ?
> y=long(x)
>ValueError: invalid literal for long(): 0xe10ea210[color=green][color=darkred]
>>>>[/color][/color]
>
>What am I doing wrong?
>[/color]
Need to supply base if converting string that is not base 10
[color=blue][color=green][color=darkred]
>>> long('123')[/color][/color][/color]
123L[color=blue][color=green][color=darkred]
>>> long('0xe10ea21 0',16)[/color][/color][/color]
3775832592L


Regards,
Bengt Richter

Re: python 2.2 string conversion ?

ken wrote:[color=blue]
> I've been looking for a solution to a string to long conversion problem that
> I've run into[color=green][color=darkred]
>>>>x = 'e10ea210'
>>>>print x[/color][/color]
> e10ea210[color=green][color=darkred]
>>>>y=long(x)[/color][/color]
>[/color]
How about:
y = long(x, 16)

Re: python 2.2 string conversion ?

>[color=blue][color=green][color=darkred]
> >>> x="e10ea210"
> >>> y=long(x)[/color][/color]
>
> Traceback (most recent call last):
> File "<pyshell#7 >", line 1, in ?
> y=long(x)
> ValueError: invalid literal for long(): e10ea210[/color]
[color=blue]
> What am I doing wrong?[/color]

You didn't specify what you are trying to do here, but I'll make a
wild *guess* that the string in x is a hexadecimal (i.e., base 16)
value. However, Python can't go around making such a guess, so you
have to explicitly specify your radix (radix being another term for
base) like this:
[color=blue][color=green][color=darkred]
>>> print long("e10ea210" ,16)[/color][/color][/color]
3775832592

or tell it to infer the radix from a '0x' prefix:
[color=blue][color=green][color=darkred]
>>> print long("0xe10ea21 0",0)[/color][/color][/color]
3775832592

Here are the relevant portions of the manual:

long(x[, radix])

Convert a string or number to a long integer. If the argument is a
string, it must contain a possibly signed number of arbitrary size,
possibly embedded in whitespace; this behaves identical to
string.atol(x). The radix argument is interpreted in the same way as
for int(), and may only be given when x is a string. Otherwise, the
argument may be a plain or long integer or a floating point number,
and a long integer with the same value is returned. Conversion of
floating point numbers to integers truncates (towards zero).


int(x[, radix])

Convert a string or number to a plain integer. If the argument is a
string, it must contain a possibly signed decimal number
representable as a Python integer, possibly embedded in whitespace;
this behaves identical to string.atoi(x[, radix]). The radix
parameter gives the base for the conversion and may be any integer
in the range [2, 36], or zero. If radix is zero, the proper radix is
guessed based on the contents of string; the interpretation is the
same as for integer literals. If radix is specified and x is not a
string, TypeError is raised. Otherwise, the argument may be a plain
or long integer or a floating point number. Conversion of floating
point numbers to integers truncates (towards zero). If the argument
is outside the integer range a long object will be returned instead.


Gary Herron

Re: python 2.2 string conversion ?

It wasn't clear to me when I read the docs - I inferred that the long()
built-in only took 1 parameter.

Thanks everybody.

"Gary Herron" <gherron@island training.com> wrote in message
news:mailman.10 59027097.828.py [email protected] ...[color=blue][color=green]
> >[color=darkred]
> > >>> x="e10ea210"
> > >>> y=long(x)[/color]
> >
> > Traceback (most recent call last):
> > File "<pyshell#7 >", line 1, in ?
> > y=long(x)
> > ValueError: invalid literal for long(): e10ea210[/color]
>[color=green]
> > What am I doing wrong?[/color]
>
> You didn't specify what you are trying to do here, but I'll make a
> wild *guess* that the string in x is a hexadecimal (i.e., base 16)
> value. However, Python can't go around making such a guess, so you
> have to explicitly specify your radix (radix being another term for
> base) like this:
>[color=green][color=darkred]
> >>> print long("e10ea210" ,16)[/color][/color]
> 3775832592
>
> or tell it to infer the radix from a '0x' prefix:
>[color=green][color=darkred]
> >>> print long("0xe10ea21 0",0)[/color][/color]
> 3775832592
>
> Here are the relevant portions of the manual:
>
> long(x[, radix])
>
> Convert a string or number to a long integer. If the argument is a
> string, it must contain a possibly signed number of arbitrary size,
> possibly embedded in whitespace; this behaves identical to
> string.atol(x). The radix argument is interpreted in the same way as
> for int(), and may only be given when x is a string. Otherwise, the
> argument may be a plain or long integer or a floating point number,
> and a long integer with the same value is returned. Conversion of
> floating point numbers to integers truncates (towards zero).
>
>
> int(x[, radix])
>
> Convert a string or number to a plain integer. If the argument is a
> string, it must contain a possibly signed decimal number
> representable as a Python integer, possibly embedded in whitespace;
> this behaves identical to string.atoi(x[, radix]). The radix
> parameter gives the base for the conversion and may be any integer
> in the range [2, 36], or zero. If radix is zero, the proper radix is
> guessed based on the contents of string; the interpretation is the
> same as for integer literals. If radix is specified and x is not a
> string, TypeError is raised. Otherwise, the argument may be a plain
> or long integer or a floating point number. Conversion of floating
> point numbers to integers truncates (towards zero). If the argument
> is outside the integer range a long object will be returned instead.
>
>
> Gary Herron
>
>
>
>[/color]