I too had this issue in PyCharm. This issue is because you don't have tkinter module in your machine.
To install follow the steps given below (select your appropriate os)
For ubuntu users
sudo apt-get install python-tk
or
sudo apt-get install python3-tk
For Centos users
sudo yum install python-tkinter
or
sudo yum install python3-tkinter
For Windows, use pip to install tk
After installing tkinter restart your Pycharm and run your code, it will work