Django how to phasing the dollar sign using os.environ.get( )

I'm coding Django program,code is running in Linux, the env file includes :

 "PWD=uTfa$aB67"

in settings.py:

PWD = os.environ.get('PWD')

Then in the code where I need this password ,I code:

password = settings.PWD

However every time when I print 'password' ,I only got:

uTfa

I have tried single quotes ,but it not works. Any suggestion ?