methods in polynomial module

[Yash Aggarwal]

A polynomial should not include division and poly() function seems to raise an error when such an argument is given to it. But several other functions like degree() gives buggy result instead of raising an error. Shouldn't they too raise an error?

>>> a=(x+1)**5/(x-3)

>>> poly(a)

Traceback (most recent call last):

  File "<stdin>", line 1, in <module>

  File "/usr/local/lib/python3.5/dist-packages/sympy-1.0.1.dev0-py3.5.egg/sympy/polys/polytools.py", line 6889, in poly

    return _poly(expr, opt)

  File "/usr/local/lib/python3.5/dist-packages/sympy-1.0.1.dev0-py3.5.egg/sympy/polys/polytools.py", line 6839, in _poly

    _poly(factor.base, opt).pow(factor.exp))

  File "/usr/local/lib/python3.5/dist-packages/sympy-1.0.1.dev0-py3.5.egg/sympy/polys/polytools.py", line 1404, in pow

    result = f.rep.pow(n)

  File "/usr/local/lib/python3.5/dist-packages/sympy-1.0.1.dev0-py3.5.egg/sympy/polys/polyclasses.py", line 446, in pow

    return f.per(dmp_pow(f.rep, n, f.lev, f.dom))

  File "/usr/local/lib/python3.5/dist-packages/sympy-1.0.1.dev0-py3.5.egg/sympy/polys/densearith.py", line 978, in dmp_pow

    return dup_pow(f, n, K)

  File "/usr/local/lib/python3.5/dist-packages/sympy-1.0.1.dev0-py3.5.egg/sympy/polys/densearith.py", line 943, in dup_pow

    raise ValueError("can't raise polynomial to a negative power")

ValueError: can't raise polynomial to a negative power

>>> degree(a)

5

>>> LT(a)

x**5/(x - 3)