sympy:表达简化

Question

我从sympy python lib开始.

如果,我有这个表达

from sympy.abc import a,b,c,p,q
e = p * ( a + b ) + q * ( a + c )

我怎么能a,b,c用作因子？喜欢

a(p+q) + b*p + c*q

Answer 1

from sympy.abc import a,b,c,p,q
from sympy import collect, expand
e = p * ( a + b ) + q * ( a + c )

print e
print expand(e)
print collect(expand(e),a)