[sympy] navitaing though sympy expression

2010-06-15 Thread nelson
hi all! i am evaluating sympy for a project i'm doing. Basically i want to be able to extract a part of an expression, for examplre (x+1)^2 out of (x+2)*(x+1)^2 and performing an operation on it. For example,, expanding the (x+1)^2 term wold return the expression (x+2)*(x^2+2*x+1) is it

Re: [sympy] navitaing though sympy expression

2010-06-15 Thread Aaron S. Meurer
Hi. The easiest way to do this is to use .args: In [1]: a = (x + 2)*(x + 1)**2 In [2]: a Out[2]: 2 (1 + x) ⋅(2 + x) In [3]: a.args Out[3]: ⎛ 2 ⎞ ⎝(1 + x) , 2 + x⎠ In [4]: a.args[0] Out[4]: 2 (1 + x) In [5]: a.args[0].expand()*a.args[1] Out[5]: ⎛