Euler method of approximating Diff. Eq.s -- MK's cut

Euler.py

from __future__ import division
# Euler method of approximating Diff. Eq.s
# Uses eval to reduce f(x,y) -- is this okay?

def euler(eq, x, y, h, e):
	while x < e:
		eqResult = eval(eq)
		x = x + h
		y = y + (h*eqResult)

	return y

print euler("e**x+2*y**2", 0, 1, .1, .4)