def Euler(x0,xf,y0,n,f):
    x=x0
    y=y0
    h=(xf-x0)/float(n)
    abscisse=[x0]
    ordonnee=[y0]
    for i in range(n):
        x=x+h
        y=y+h*f(x,y)
        abscisse.append(x)
        ordonnee.append(y)
    return ordonnee