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]> wrote: > Hi, > > On 8 October 2014 12:05, <[email protected]> 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]. >> 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/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]. > 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/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/CAKgW%3D6JVYP9bA5_sio0KZkJD%2BA-NiacxHsz%2B65xK9wR4mme2_w%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
