Python2 doesn't work when both python3.8 and python2.7 are installed on Anaconda3

Question

I installed Anaconda and used Python3.8.8 as the base environment, now I create a new environment named py27 to install python2.7, but it doesn't work.

Here are the details

(base) C:\Windows\System32>conda env list
# conda environments:
#
base                  *  C:\ProgramData\Anaconda3
pix2vox                  C:\Users\10531\.conda\envs\pix2vox
py27                     C:\Users\10531\.conda\envs\py27


(base) C:\Windows\System32>python
Python 3.8.8 (default, Apr 13 2021, 15:08:03) [MSC v.1916 64 bit (AMD64)] :: Anaconda, Inc. on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()

(base) C:\Windows\System32>conda activate py27

(py27) C:\Windows\System32>python
  File "C:\ProgramData\Anaconda3\lib\site.py", line 178
    file=sys.stderr)
        ^
SyntaxError: invalid syntax

(py27) C:\Windows\System32>

My environment variable PATH contains

C:\ProgramData\Anaconda3;
C:\ProgramData\Anaconda3\Scripts;
C:\ProgramData\Anaconda3\Library\mingw-w64\bin;
C:\ProgramData\Anaconda3\Library\usr\bin;
C:\ProgramData\Anaconda3\Library\bin;

I want to use both python3.8 and python2.7 simultaneously, please help me, thanks!

Answer 1

I fixed it.

1. Delete the PYTHONHOME environment variable, I set it as C:\ProgramData\Anaconda3; before.

2. Delete

C:\ProgramData\Anaconda3\Library\mingw-w64\bin;
C:\ProgramData\Anaconda3\Library\usr\bin;
C:\ProgramData\Anaconda3\Library\bin;

in Path, I didn't know if it works, but I did it.

3. Add new entries

C:\Users\10531\.conda\envs\py27;
C:\Users\10531\.conda\envs\py27\Scripts;

in PATH.

4. Rerun the terminal.