如何在python中计算平均值？

我有一个列表,我想计算她的值的平均值(平均值？).当我这样做:

import numpy as np #in the beginning of the code

goodPix = ['96.7958', '97.4333', '96.7938', '96.2792', '97.2292']
PixAvg = np.mean(goodPix)

我收到此错误代码:

ret = um.add.reduce(arr, axis=axis, dtype=dtype, out=out, keepdims=keepdims)

TypeError: cannot perform reduce with flexible type

我试图找到一些帮助,但没有找到有用的东西

谢谢你们.