关于mac上python安装django模块的问题

！！！紧急！！！

我折腾了2个多小时都还没弄好的环境问题！

我跟着书《Python编程从入门到实践》的第十八章安装django模块，进行到创建数据库的时候，在终端中输入python manage.py.migrate，会显示Traceback (most recent call last):
File "manage.py", line 8, in <module>
from django.core.management import execute_from_command_line
ModuleNotFoundError: No module named 'django'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "manage.py", line 14, in <module>
import django
ModuleNotFoundError: No module named 'django'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "manage.py", line 17, in <module>
"Couldn't import Django. Are you sure it's installed and "
ImportError: Couldn't import Django. Are you sure it's installed and available on your PYTHONPATH environment variable? Did you forget to activate a virtual environment?

我百度了很多 升级 环境变量都不行 都安装了django模块 但老是显示没有安装 要给弄崩溃了，有大神能教教怎么回事