When the source code Matplotlib has the following parameters for setting Chinese or negative numbers, a NameError will appear in pyinstaller packaging: name ‘defaultparams’ is not defined error

plt.rcParams['font.sans-serif'] = ['STSong']  
plt.rcParams['axes.unicode_minus'] = False  

Solution:

Reduce Matplotlib to version 3.2.2

conda install matplotlib==3.2.2

Note: pyinstaller 3.6 version    Python 3.6.13 version