Macで以下のように仮想環境を構築して python を実行して import tkinter をするとエラーになります。
$ python3 -m venv venv
$ source venv/bin/activate
(venv) $ python
Python 3.7.3 (default, Apr 7 2020, 14:06:47)
[Clang 11.0.3 (clang-1103.0.32.59)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import tkinter
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/Applications/Xcode.app/Contents/Developer/Library/Frameworks/Python3.framework/Versions/3.7/lib/python3.7/tkinter/__init__.py", line 36, in <module>
import _tkinter # If this fails your Python may not be configured for Tk
ModuleNotFoundError: No module named '_tkinter'
>>>
どうしたら良いでしょうか。