从命令行运行Python找不到库

Question

我知道我已经安装了matplotlib（例如，我可以使用ipython进行导入），但今天早些时候我升级到了python 3.7，看起来我弄坏了一些东西：

> python plot_spectra.py 
Traceback (most recent call last):
  File "plot_spectra.py", line 3, in <module>
    import matplotlib.pyplot as plt
ModuleNotFoundError: No module named 'matplotlib'


~ > which python
/Users/npr1/anaconda3/bin/python
~ > which python2
/usr/local/bin/python2
~ > which python3
/Library/Frameworks/Python.framework/Versions/3.7/bin/python3

建议？ 谢谢