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Cannot activate environment in anaconda prompt

I input python in cmd and it shows a warning:
C:\Users\sky>python
Python 3.8.8 (default, Apr 13 2021, 15:08:03) [MSC v.1916 64 bit (AMD64)] :: Anaconda, Inc. on win32
Warning:
This Python interpreter is in a conda environment, but the environment has
not been activated. Libraries may fail to load. To activate this environment
please see https://conda.io/activation
Type "help", "copyright", "credits" or "license" for more information.
>>>
I cannot use pip install any packages, I thought maybe that's the problem. So I checked the information at the link:https://conda.io/activation
and followed the instruction:
c:\Anaconda3\Scripts\activate base
It said 'system cannot find the path'. I searched for the files in that path and found two of them are named 'activate'. So I input
c:\Anaconda3\Scripts\activate
but still,'system cannot find the path'.
How to activate the conda environment? I really need some help. Thanks

In a clean Anaconda installation you should have condabin only, e.g.
C:\Anaconda3\condabin
on your system path. To activate the base environment from the command prompt you use
C:\> conda activate
(base) C:\>
This will add the following folders to your system path too:
C:\Anaconda3;
C:\Anaconda3\Library\mingw-w64\bin;
C:\Anaconda3\Library\usr\bin;
C:\Anaconda3\Library\bin;
C:\Anaconda3\Scripts;
Only now you you are ready to run python and import all your packages properly.
The same thing typically happens when you select Anaconda prompt from your programs menu.

Resolving errors in python environment on Windows

I just started having some problems with python, and would like to fix this the proper way, as a last resort, reinstalling if I have to.
Before Python 3, I had Python 2.7 installed. I then installed Python 3.7 along side it. I don't remember, if the path environment was automatically set, or if i manually set it.
My system variables path contains :
C:\Python27\;C:\Python27\Scripts;
So I believe this was set automatically.
My user variables path however contains :
C:\Python37\;C:\Python37\Scripts;
Would the python installer use the user environment? I'm not sure, so I don't know if I set that myself.
However, the user variables path also contains :
%PYTHON_DIR%\Python37\Scripts\;%PYTHON_DIR%\Python37\;%PYTHON_DIR%\Python36\Scripts\;%PYTHON_DIR%\Python36\
Again, I don't know if I set this myself, and I have no recollection of setting this in my user variables :
PYTHON_DIR = C:\Users\pcuser\AppData\Local\Programs\Python
...but it's there, and I have two folders in that path.
I also have this in my user variables path :
PYTHON = os.path.expanduser(os.getenv('PYTHON', 'C:\\Python37\\python.exe'))
I know I created a python environment. I just have to look for it, as I don't remember where to find it right now.
Here is the problem I am having.
I also am using Python in MSYS, and get this error from Python in C:\msys64\usr\bin :
Could not find platform independent libraries <prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Fatal Python error: initfsencoding: Unable to get the locale encoding
ModuleNotFoundError: No module named 'encodings'
Current thread 0x0000000800018040 (most recent call first):
0 [main] python 1489 cygwin_exception::open_stackdumpfile: Dumping stack t
race to python.exe.stackdump
I set PYTHONHOME to C:\msys64\usr\bin. That doesn't solve the problem.
I also removed PYTHON_DIR to see if there was a conflict there, but that didn't solve the problem.
Rather, I got another error :
Fatal Python error: initfsencoding: Unable to get the locale encoding
ModuleNotFoundError: No module named 'encodings'
Current thread 0x0000000800018040 (most recent call first):
0 [main] python 143 cygwin_exception::open_stackdumpfile: Dumping stack tr
ace to python.exe.stackdump
So it seems to me my Python environment is messed up, and I want to learn how to set it up correctly, hopefully without having to start over.
How can I get rid of these errors, and get a proper python environment?

Personally, I use miniconda.
Miniconda is the small version of anaconda which is an excellent environment manager. Miniconda does not include a gui and I feel it is nicer to work with.
To create an environment with
conda create -n my-test-env python=3.9
You can activate it using
conda activate my-test-env
You can install other packages using
conda install numpy.
However, not all python packages are available in conda. You can any pip packages by installing pip
conda install pip
pip install numpy

Setting PYTHONHOME to a value like C:\msys64\usr\bin is definitely wrong; it should be something like C:\Python37\Lib if that's where Python installed its libraries. But try simply unsetting it.

After a while of troubleshooting, I was able to discover where the problem was.
Some files in C:\msys64\usr\lib\python3.8 somehow got deleted, or python 3.8 was installed, but not properly. So I did a reinstall, and python stopped complaining about missing encodings and modules.
Running a test on all python installations
MINGW64 ~
# python
Python 3.8.2 (default, Feb 27 2020, 05:27:33) [GCC 9.2.0 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>
# python setup_build.py install
running install
running build
running build_ext
skipping 'geotools/geotools.c' Cython extension (up-to-date)
running install_lib
copying build/lib.mingw-3.8/geotools-cpython-38.dll -> C:/msys64/mingw64/lib/python3.8/site-packages
running install_egg_info
Writing C:/msys64/mingw64/lib/python3.8/site-packages/geotools-0.1.0-py3.8.egg-info
MINGW32 ~
# python
Python 3.8.2 (default, Feb 27 2020, 06:39:26) [GCC 9.2.0 32 bit] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>
# python setup_build.py install
running install
running build
running build_ext
dllwrap: WARNING: dllwrap is deprecated, use gcc -shared or ld -shared instead
skipping 'geotools/geotools.c' Cython extension (up-to-date)
running install_lib
running install_egg_info
Removing C:/msys64/mingw32/lib/python3.8/site-packages/geotools-0.1.0-py3.8.egg-info
Writing C:/msys64/mingw32/lib/python3.8/site-packages/geotools-0.1.0-py3.8.egg-info
C:\WINDOWS\system32>py -3.7 -m pip list
Package Version
----------------------------- ---------
...
C:\WINDOWS\system32>py -2.7 -m pip list
DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020. Please
upgrade your Python as Python 2.7 is no longer maintained. pip 21.0 will drop s
upport for Python 2.7 in January 2021. More details about Python 2 support in pi
p can be found at https://pip.pypa.io/en/latest/development/release-process/#pyt
hon-2-support pip 21.0 will remove support for this functionality.
Package Version
----------------------------- ----------
...
C:\WINDOWS\system32>python
Python 2.7.14 (v2.7.14:84471935ed, Sep 16 2017, 20:25:58) [MSC v.1500 64 bit (AM
D64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.path
['', 'C:\\WINDOWS\\SYSTEM32\\python27.zip', 'C:\\Python27\\DLLs', 'C:\\Python27\
\lib', 'C:\\Python27\\lib\\plat-win', 'C:\\Python27\\lib\\lib-tk', 'C:\\Python27
', 'C:\\Users\\pcUser\\AppData\\Roaming\\Python\\Python27\\site-packages', 'C:\\Py
thon27\\lib\\site-packages', 'C:\\Python27\\lib\\site-packages\\pybind11-2.6.2-p
y2.7.egg']
>>>
C:\WINDOWS\system32>py -3
Python 3.7.7 (tags/v3.7.7:d7c567b08f, Mar 10 2020, 10:41:24) [MSC v.1900 64 bit
(AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.path
['', 'C:\\Users\\pcUser\\AppData\\Local\\Programs\\Python\\Python37\\python37.zip'
, 'C:\\Users\\pcUser\\AppData\\Local\\Programs\\Python\\Python37\\DLLs', 'C:\\User
s\\pcUser\\AppData\\Local\\Programs\\Python\\Python37\\lib', 'C:\\Users\\pcUser\\App
Data\\Local\\Programs\\Python\\Python37', 'C:\\Users\\pcUser\\AppData\\Roaming\\Py
thon\\Python37\\site-packages', 'C:\\Users\\pcUser\\AppData\\Local\\Programs\\Pyth
on\\Python37\\lib\\site-packages']
>>>
C:\WINDOWS\system32>py -3.6 -m pip list
Package Version
--------------- --------
...
My python environment is good. All working nicely. :)
What I learned...
Using PYTHONHOME and PYTHONPATH is not neccesary, as was suggested by many... although equally suggessted by many.
From my experience - speaking fron a novice perspective - I would not recommend using them.
Maybe they work for others, but I got errors regardless of how I set it up - whether
C:\Python37 or
C:\Python37\lib or
C:\Users\pcUser\AppData\Local\Programs\Python\Python37 or
C:\msys64\usr\lib\python3.8;C:\msys64\usr\lib\python3.8\site-packages;C:\msys64\usr\lib\python3.8\lib-dynload;C:\msys64\usr\lib\python3.8\distutils
They all return a heap of errors on one installment or other.
So it does not work for me. However, probably works for others.
I am happy though that after probably more than 60 hours, my python environment is back in working order. :)

Conda packages in .local

I am using miniconda to create several environments, all of which with Python 3.7. I found that for each env, the installed packages go to .local path, which means for different envs of Python 3.7, they share the same collections of packages.
For example:
Python 3.7.7 (default, May 7 2020, 21:25:33) [GCC 7.3.0] :: Anaconda, Inc. on linux Type "help", "copyright", "credits" or "license" for more information.
>>> import numpy as np
>>> np.__file__ '/home/my_name/.local/lib/python3.7/site-packages/numpy/__init__.py'
I suppose the installed packages should be in miniconda's directory, not my local .local directory.

How are you installing the packages? Are you using ‘conda env create’ for each new environment? You may need to check that the ‘base’ conda environment is running on your terminal, maybe you are using the default python interpreter instead of miniconda.
Also, if you are don’t have a specific reason to use conda, and just want it to manage virtual environments and packages, I would suggest that you try ‘pipenv’ instead. I found it to be simpler than conda and isolates pretty well the virtual environments.

Spyder reports invalid alias when running any script

I can't tell why this is happening but it seems to have started when I updated (everything - conda update --all). It had been about 1 year since I last had updated. Something must have changed.
Here is the script:
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Sun Mar 3 11:25:22 2019
#author: pitosalas
"""
print("hello")
And here is the output from pressing the green triangle in spyder:
Python 3.6.6 |Anaconda, Inc.| (default, Jun 28 2018, 11:07:29)
Type "copyright", "credits" or "license" for more information.
IPython 7.3.0 -- An enhanced Interactive Python.
runfile('/Users/pitosalas/Box Sync/datawork/2019Resubmit/deleteme.py', wdir='/Users/pitosalas/Box Sync/datawork/2019Resubmit')
ERROR:root:Invalid alias: The name clear can't be aliased because it is another magic command.
ERROR:root:Invalid alias: The name more can't be aliased because it is another magic command.
ERROR:root:Invalid alias: The name less can't be aliased because it is another magic command.
ERROR:root:Invalid alias: The name man can't be aliased because it is another magic command.
hello

I met same situation today, and I checked as following.
conda create -n testenv python spyder ipython=7.3
The issue happen.
conda create -n testenv python spyder ipython=7.2.0
In this environment, it doesn't happen.
I recommend you to rebuild your environment using ipython7.2.0 or downgrade with this:
conda install ipython=7.2.0

As indicated on the issue tracker, IPython 7.7.0 sorted out this problem. I can confirm updating to 7.7.0 worked for me (conda 4.7.10 on Ubuntu 18.04, Spyder 3.3.6).

The root cause can be traced down to this commit to ipython. Downgrading to ipython=7.2.0 certainly helps. Hope this can be fixed soon.

conda install ipython=7.2.0 worked for me. ipython 7.3.0 was the culprit.

Django, Pyenv and Git file structure on Ubuntu

I am working to set up a django project on ec2 with an Ubuntu 14.4 LTS instance. I want to write my code using python 3 and django. I've been advised that the best way to do this is to use a virtualenv. Following
https://robinwinslow.co.uk/2013/12/26/python-3-4-virtual-environment/
I tried:
~$ pyvenv-3.4 djenv
Which appears to create a virtualenv (please see screenshot). Now I have 2 questions:
1) What folder should I place my django project. - I'm thinking within the djenv folder. In other words I'd run:
/home/ubuntu/djenv$ django-admin.py startproject testproject.
2) init a git repository. I'm assuming I'd to it it in the same location, i.e.
/home/ubuntu/djenv$ git init
from within
Does this seem correct or is there a better way to do this?

Your project source code should be entirely separate from your virtual env in the file system. If they are in the same place, as you suggest, then you will end up checking libraries into your git repository needlessly and that will take up extra space end up causing problems.
Once you have activated a virtualenv you can run Python and use all the libraries in it. You don't need any connection in the file system.
You should store a PIP file in your git repo somewhere that describes how to install the relevant dependencies into your virtualenv so you can re-create it on another machine.
On my machine my projects are in /home/me/projects/«project» and my virtualenvs are in /home/me/envs/«envname». I use virtualenvwrapper which makes things easy.
Create an environment
$ mkvirtualenv test
New python executable in test/bin/python
Installing Setuptools......done.
Installing Pip.........done.
Activate it
$ workon test
Python now refers to the one in my environment. It has its own site-packages etc.
$ which python
/Users/joe/Envs/test/bin/python
If we run it and look at the paths, they point to the virtualenv. This is where it looks for packages (lots removed from my path for simplicity).
$ python
Python 2.7.5 (default, Mar 9 2014, 22:15:05)
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.0.68)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.path
['', '/Users/joe/Envs/test/lib/python27.zip', '/Users/joe/Envs/test/lib/python2.7', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7', '/Users/joe/Envs/test/lib/python2.7/site-packages']
>>>