>>> from sympy.parsing.sympy_parser import parse_expr
>>> parse_expr("(-6x^2-x-7)(2x^3+3x^2-2x-5)")
Traceback (most recent call last):
File "<pyshell#25>", line 1, in <module>
parse_expr("(-6x^2-x-7)(2x^3+3x^2-2x-5)")
File "C:\Python34\lib\site-packages\sympy\parsing\sympy_parser.py", line
757, in parse_expr
return eval_expr(code, local_dict, global_dict)
File "C:\Python34\lib\site-packages\sympy\parsing\sympy_parser.py", line
691, in eval_expr
code, global_dict, local_dict) # take local objects in preference
File "<string>", line 1
(-Integer (6 )Symbol ('x' )^Integer (2 )-Symbol ('x' )-Integer (7
))(Integer (2 )Symbol ('x' )^Integer (3 )+Integer (3 )Symbol ('x' )^Integer
(2 )-Integer (2 )Symbol ('x' )-Integer (5 ))
^
SyntaxError: invalid syntax
>>>
在 2014年10月9日星期四UTC+8上午3时37分07秒，Aaron Meurer写道：
>
> Have a look at parse_expr() in sympy.parsing.sympy_parser.
>
> Aaron Meurer
>
> On Wed, Oct 8, 2014 at 8:42 AM, Mateusz Paprocki <[email protected]
> <javascript:>> wrote:
> > Hi,
> >
> > On 8 October 2014 12:05, <[email protected] <javascript:>> wrote:
> >> Is there any function in SymPy can take this TEX command as an input
> >>
> >> (-6x^2-x-7)(2x^3+3x^2-2x-5)
> >>
> >> to find the derivative?
> >
> > I wanted to suggest a mathematica parser for this:
> >
> > In [1]: import sympy.parsing.mathematica as m
> >
> > In [2]: m.parse("(-6x^2-x-7)(2x^3+3x^2-2x-5)")
> > Out[2]: '(-6*x**2-x-7)*(2*x**3+3*x**2-2*x-5)'
> >
> > In [3]: eval(_)
> > Out[3]:
> > ⎛ 2 ⎞ ⎛ 3 2 ⎞
> > ⎝- 6⋅x - x - 7⎠⋅⎝2⋅x + 3⋅x - 2⋅x - 5⎠
> >
> > But there is bug there and the above output requires the following
> patch:
> >
> > diff --git a/sympy/parsing/mathematica.py b/sympy/parsing/mathematica.py
> > index f86d59a..eeb12f7 100644
> > --- a/sympy/parsing/mathematica.py
> > +++ b/sympy/parsing/mathematica.py
> > @@ -39,7 +39,7 @@ def parse(s):
> > (r"\A\((.+)\)([\w\.].*)\Z", # Implied multiplication - (a)b
> > lambda m: "(" + parse(m.group(1)) + ")*" + parse(m.group(2))),
> >
> > - (r"\A([\d\.]+)([a-zA-Z].*)\Z", # Implied multiplicatin - 2a
> > + (r"\A([+-]?[\d\.]+)([a-zA-Z].*)\Z", # Implied multiplicatin -
> 2a
> > lambda m: parse(m.group(1)) + "*" + parse(m.group(2))),
> >
> > (r"\A([^=]+)([\^\-\*/\+=]=?)(.+)\Z", # Infix operator
> >
> > Mateusz
> >
> >> --
> >> You received this message because you are subscribed to the Google
> Groups
> >> "sympy" group.
> >> To unsubscribe from this group and stop receiving emails from it, send
> an
> >> email to [email protected] <javascript:>.
> >> To post to this group, send email to [email protected]
> <javascript:>.
> >> Visit this group at http://groups.google.com/group/sympy.
> >> To view this discussion on the web visit
> >>
> https://groups.google.com/d/msgid/sympy/04e0cbd4-5b6b-4418-8166-024a0729aff8%40googlegroups.com.
>
>
> >> For more options, visit https://groups.google.com/d/optout.
> >
> > --
> > You received this message because you are subscribed to the Google
> Groups "sympy" group.
> > To unsubscribe from this group and stop receiving emails from it, send
> an email to [email protected] <javascript:>.
> > To post to this group, send email to [email protected]
> <javascript:>.
> > Visit this group at http://groups.google.com/group/sympy.
> > To view this discussion on the web visit
> https://groups.google.com/d/msgid/sympy/CAGBZUCZfJVXw27Rh0U31ST9tU%3DwZbkuqUS792ff364JYvdG%2BHg%40mail.gmail.com.
>
>
> > For more options, visit https://groups.google.com/d/optout.
>
--
You received this message because you are subscribed to the Google Groups
"sympy" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sympy.
To view this discussion on the web visit
https://groups.google.com/d/msgid/sympy/041204f1-5a4d-4b1a-ac0e-fecf690a037a%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
