You should juste write import serial instead of import pyserial.
I have not managed to install pyserial for use with Spyder 3.9 (launched from Anaconda.Navigator) in Windows 10.
I tried <conda install -c conda-forge pyserial> from the Windows command terminal and some files were installed, but import pyserial from the Spyder console gives the response <ModuleNotFoundError: No module named 'pyserial'>.
Then I tried to install it again from the Spyder console with pip install pyserial, which gave the response <Requirement already satisfied: pyserial in c:\users\father\anaconda3\lib\site-packages (3.4)>
Then I tried pip uninstall pyserial, which locked up the Spyder console altogether.
I'm afraid it looks a bit of a mess.  Can anybody suggest how to clear it up and make pyserial available?
trouble installing pyserial