jbar = 50

dx=1.0; dt=0.1; sig=1.0; endtime=10.0; time=0.0; TL=400.0; TR=0.0

T = [ 0.00 for j in range(0, jbar + 2) ]
Tnew = T[:]
j = jbar

while time < endtime:
  T[0] = 2.0*TL - T[1]
  T[jbar+1] = 2.0*TR-T[jbar]
  for j in range(1, jbar+1):
    Tnew[j] = T[j] + sig*dt*(T[j+1]+T[j-1]-2.0*T[j])/dx/dx;
  for j in range(1, jbar): T[j] = Tnew[j]
  time += dt
for j in range(1, jbar+1):
  print "x %11.6lf T %11.6lf" % (((j-1)+0.5)*dx, T[j])