Python 2 while循环在第二次迭代中失败

我创建了一个程序,要求用户进行温度猜测(空间温度),然后计算这个温度的黑体光谱,并返回与测量数据的均方根偏差。然后要求用户再次猜测:

这是输入的代码,因为我还不能嵌入图像:

while True:
  temperature_guess = input("What is the temperature of the black body spectrum of space (in kelvin)?\
  Type 'stop' when you're happy with your estimate.")

  if temperature_guess == "stop":
    break

  else:
    T_guess = float(temperature_guess)

    print T_guess

    # Calculate intensities produced from measured wavelengths and user guess temperature

    intensities_guess=radiation(measured_lambda_metres,T_guess)

    print intensities_guess

    # Calculate root mean square deviation from measured values

    rmsd = rmsd(measured_intensity, intensities_guess)

    print "For your guessed temperature of" , T_guess , "kelvin, \
    the root mean square deviation from measured intensity data is" , "%.4g" %rmsd , \
    "to 4 significant figures."

程序在一次迭代中运行良好(一次温度猜测),如果我让它停止,它会很好地中断,但是如果我输入另一个温度,它会在中途停止。我可以从print命令中看到,它接受温度输入并基于此计算强度,但在均方根偏差计算中失败。