How to extract all coefficients in sympy
The easiest way is to use Poly
>>> a = Poly(expr, x)
>>> a.coeffs()
[1, 2*a + 1, 3]
all_coeffs()
can be sometime better than using coeffs()
for a Poly
.
The difference lies in output of these both. coeffs()
returns a list containing all coefficients which has a value and ignores those whose coefficient is 0
whereas all_coeffs()
returns all coefficients including those whose coefficient is zero.
>>> a = Poly(x**3 + a*x**2 - b, x)
>>> a.coeffs()
[1, a, -b]
>>> a.all_coeffs()
[1, a, 0, -b]