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ModuleNotFoundError: No module named 'pandas._libs.interval'

Suddenly, I can't import pandas in python. I am using anaconda as package manager, but it seems that no matter how many times I uninstall and install pandas, I still get the same error:
(base) C:\>conda install pandas
Collecting package metadata (current_repodata.json): done
Solving environment: done
## Package Plan ##
environment location: C:\Users\au207178\Anaconda3
added / updated specs:
- pandas
The following NEW packages will be INSTALLED:
blas pkgs/main/win-64::blas-1.0-mkl
bottleneck pkgs/main/win-64::bottleneck-1.3.2-py38h2a96729_1
intel-openmp pkgs/main/win-64::intel-openmp-2021.4.0-haa95532_3556
mkl pkgs/main/win-64::mkl-2021.4.0-haa95532_640
mkl-service pkgs/main/win-64::mkl-service-2.4.0-py38h2bbff1b_0
mkl_fft pkgs/main/win-64::mkl_fft-1.3.1-py38h277e83a_0
mkl_random pkgs/main/win-64::mkl_random-1.2.2-py38hf11a4ad_0
numexpr pkgs/main/win-64::numexpr-2.8.1-py38hb80d3ca_0
numpy pkgs/main/win-64::numpy-1.21.2-py38hfca59bb_0
numpy-base pkgs/main/win-64::numpy-base-1.21.2-py38h0829f74_0
pandas pkgs/main/win-64::pandas-1.3.5-py38h6214cd6_0
Proceed ([y]/n)? y
Preparing transaction: done
Verifying transaction: done
Executing transaction: done
(base) C:\>python
Python 3.8.12 (default, Oct 12 2021, 03:01:40) [MSC v.1916 64 bit (AMD64)] :: Anaconda, Inc. on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import pandas
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Users\au207178\AppData\Roaming\Python\Python310\site-packages\pandas\__init__.py", line 22, in <module>
from pandas.compat import (
File "C:\Users\au207178\AppData\Roaming\Python\Python310\site-packages\pandas\compat\__init__.py", line 15, in <module>
from pandas.compat.numpy import (
File "C:\Users\au207178\AppData\Roaming\Python\Python310\site-packages\pandas\compat\numpy\__init__.py", line 7, in <module>
from pandas.util.version import Version
File "C:\Users\au207178\AppData\Roaming\Python\Python310\site-packages\pandas\util\__init__.py", line 1, in <module>
from pandas.util._decorators import ( # noqa
File "C:\Users\au207178\AppData\Roaming\Python\Python310\site-packages\pandas\util\_decorators.py", line 14, in <module>
from pandas._libs.properties import cache_readonly # noqa
File "C:\Users\au207178\AppData\Roaming\Python\Python310\site-packages\pandas\_libs\__init__.py", line 13, in <module>
from pandas._libs.interval import Interval
ModuleNotFoundError: No module named 'pandas._libs.interval'
I have also tried running 'conda update conda'.
What's the next thing to do?
Update:
I checked, and the file is definitely there, in "C:\Users\au207178\AppData\Roaming\Python\Python310\site-packages\pandas_libs\interval.pyx".
However, I notice that part of the path to this library says 'python310'. However, my python version is 3.8.8. Is it possible that python is somehow looking in the wrong place when trying to import pandas._libs.interval? I have tried both python 3.10 (couldn't even install pandas) and python 3.9.7 (no effect).
I have also tried conda install --revision 0, which also had no effect...

Yes, it appears to be loading pandas from a user-level installation. User-level installs can leak into Conda environments and lead to unpredictable behavior, such as what you are seeing.
There are two routes of action of which I know. You may want to try the second one first, which would confirm the cause. However, the first option is likely more manageable going forward, since once it's done, the issue should be resolved.
Option 1: Remove External Python(s)
If you would like Conda to simply work as expected, then uninstall the user-level Python. Note that the one detected (Python 3.10) may not be the only one, so you may have to track down multiple copies. I'm not on Windows, so I can't suggest concrete steps for uninstallation.
However, you may be already using this user-level Python for other projects, so this option may not be practicable.
Option 2: Launch Python with Isolation Flags
There are some pertinent flags that Python provides that has it ignore the various sources that can lead to leaking in other site-packages. Here are the three important ones:
$ python --help
usage: python [option] ... [-c cmd | -m mod | file | -] [arg] ...
Options and arguments (and corresponding environment variables):
...
-E : ignore PYTHON* environment variables (such as PYTHONPATH)
-s : don't add user site directory to sys.path; also PYTHONNOUSERSITE
-S : don't imply 'import site' on initialization
...
Try them individually, or all together, and see if this fixes the issue. Individually, you may be able to narrow down whether it is due to PYTHONPATH (-E alone would fix) or generic user-level searching (-s alone would fix).
Additional Thoughts
I find it odd that a Python 3.10 installation is leaking into a Python 3.8 interpreter run. Usually, the site module only loads within matching major+minor versions (e.g., 3.8 should only pick up another 3.8). This might be indicative that something else is going on. Perhaps the PYTHONPATH environment is set? (It really never should be.)
Generally, I don't recommend using the base environment for work. This is never documented in Anaconda documentation, but it is the painful truth that many long-term Conda users come to, usually after their base either breaks or get's so overloaded with packages that it takes unreasonably long for them to upgrade the conda package. Instead, create a new environment and have that activate by default instead of base.

How can I execute python.exe to open as if I opened it from the anaconda environment named "base"?

The file path: "C:\Users\Disander\anaconda3\python.exe"
When I open python from the path above, python shows the following warning:
Python 3.7.6 (default, Jan 8 2020, 20:23:39) [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.
>>>
Then when I try to import numpy or pandas, it throws the following error:
Traceback (most recent call last):
File "C:\Users\Disander\anaconda3\lib\site-packages\numpy\core\__init__.py", line 24, in <module>
from . import multiarray
File "C:\Users\Disander\anaconda3\lib\site-packages\numpy\core\multiarray.py", line 14, in <module>
from . import overrides
File "C:\Users\Disander\anaconda3\lib\site-packages\numpy\core\overrides.py", line 7, in <module>
from numpy.core._multiarray_umath import (
ImportError: DLL load failed: The specified module could not be found.
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Users\Disander\anaconda3\lib\site-packages\numpy\__init__.py", line 142, in <module>
from . import core
File "C:\Users\Disander\anaconda3\lib\site-packages\numpy\core\__init__.py", line 54, in <module>
raise ImportError(msg)
ImportError:
IMPORTANT: PLEASE READ THIS FOR ADVICE ON HOW TO SOLVE THIS ISSUE!
Importing the numpy c-extensions failed.
- Try uninstalling and reinstalling numpy.
- If you have already done that, then:
1. Check that you expected to use Python3.7 from "C:\Users\Disander\anaconda3\python.exe",
and that you have no directories in your PATH or PYTHONPATH that can
interfere with the Python and numpy version "1.18.1" you're trying to use.
2. If (1) looks fine, you can open a new issue at
https://github.com/numpy/numpy/issues. Please include details on:
- how you installed Python
- how you installed numpy
- your operating system
- whether or not you have multiple versions of Python installed
- if you built from source, your compiler versions and ideally a build log
- If you're working with a numpy git repository, try `git clean -xdf`
(removes all files not under version control) and rebuild numpy.
Note: this error has many possible causes, so please don't comment on
an existing issue about this - open a new one instead.
Original error was: DLL load failed: The specified module could not be found.
>>>
If I launch python from the anaconda terminal, python works perfectly fine. I show this by importin numpy and pandas. I import sys and print sys.executable to show that anaconda is using the same python executable python.exe.
(base) C:\Users\Disander>python
Python 3.7.6 (default, Jan 8 2020, 20:23:39) [MSC v.1916 64 bit (AMD64)] :: Anaconda, Inc. on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> print(sys.executable)
C:\Users\Disander\anaconda3\python.exe
>>>
>>> import numpy
>>> import pandas
>>>
I also tried to activate the (base) environment after executing python.exe. Below, I show what happened when I tried using "os.system('conda activate base')"
>>> import os
>>> os.system('conda activate base')
'conda' is not recognized as an internal or external command,
operable program or batch file.
1
>>>
I would like to know if there is a way to execute the python.exe file as if I executed it from anaconda using the (base) environment. I need this because I have another application depending on this executable. The same application uses it to import modules such as numpy and pandas but it is not working.

You need first be sure that "Scripts" folder is in your path environment (C:\Anaconda3\Scripts, for my setup).
Then
activate environment_name
in CMD should work. Replace 'environment_name' with 'base' if you want 'base' activated.

Open the Anaconda prompt or conda activate. Then print the path environment to the console via
(base) C:\> path
Add every listed folder below the Anaconda installation folder ..\Anaconda3\ to your user environment PATH variable. This will allow Python to also find numpy's C-Libraries.
\Anaconda3;
\Anaconda3\Library\mingw-w64\bin;
\Anaconda3\Library\usr\bin;
\Anaconda3\Library\bin;
\Anaconda3\Scripts;
\Anaconda3\bin;
Of cause this all ruins conda's well elaborated environment concept. So make sure you know what you're doing.
EDIT AFTER QUESTION EDIT:
If you have another application that depends on Python running in an Anacoda environment - like for example PowerBI Desktop - simply run that other application from the Anaconda prompt too.
EDIT AFTER 2ND QUESTION EDIT
If conda isn't recognized from os you clearly missed to initialize your shells via
conda init --all
Basically this is done during Anaconda installation by default, but some people prefer to skip this step for whatever reason.

Unable to import pyperclip in my python IDLE, but able to import from command prompt

This is my first question on stackoverflow and I'm new to Python.
I want to import pyperclip module.
So I went to cmd, ran as administrator, moved to the path using - cd \Program Files\Python37\Scripts and downloaded pip via pip3 install pyperclip command and it is successfully downloaded.
Now from IDLE I'm not able to import it
Following is the output from IDLE, it has not got that pyperclip module to import
Python 3.8.2 (tags/v3.8.2:7b3ab59, Feb 25 2020, 22:45:29) [MSC v.1916 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license()" for more information.
>>> import pyperclip
Traceback (most recent call last):
File "<pyshell#0>", line 1, in <module>
import pyperclip
ModuleNotFoundError: No module named 'pyperclip'
>>>
After this I did some research I found that, there could be possibility that it must have installed in some other directory. so from the research I found pyperclip folder and pyperclip-1.8.0-py3.6.egg-info folder in one of sub directory, which I copied and pasted in C:\Program Files\Python36 directory.
With above thing also I unable to import pyperclip from IDLE.
I went to command prompt, typed python and able to import it
Following is output
C:\Users\Administrator>python
Python 3.6.0 (v3.6.0:41df79263a11, Dec 23 2016, 08:06:12) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import pyperclip
>>>
So I'm not able to import from IDLE, but able to do in command prompt.
1 more problem I found as I'm new to python,
IDLE is showing python 3.8.2 and on command prompt it is showing 3.6. I have downloaded only 1 python and I have only 1 python installed. why there is this version difference 3.6 and 3.8.2
UPDATE:
With following command on IDLE, I able to import pyperclip. But it is only for current opened IDLE. After closing IDLE and reopening it, I have do these commands again. How to fix it for all time
>>> import sys
>>> sys.path.insert(1, 'C:/Program Files/Python36')
>>> import pyperclip
~~~~~~~~~~
SOLVED:

In your case, IDLE is using one Python interpreter (Python 3.8.2), while in the command-line you run another one (Python 3.6.0), with pyperclip installed. You'd be better off to do ONE of the following steps:
1) use multiple virtual environments to solve this problem easily (recommended). Read this article for more information.
2) install the required module on both Python interpreters, by running pip install pyperclip either (depending on the Python version) from C:\PythonXX\Scripts or C:\Program files\PythonXX\Scripts
3) you may also use single Python interpreter on your machine: remove one of the interpreters and then "Repair" another one (to fix the filetypes associations). To do this, open the installer from Windows uninstall manager and follow the steps it will give you.

I found 1 more python IDLE installed in directory
C:\Users\Administrator\AppData\Local\Programs\Python\Python38-32
I copied pyperclip folder and pyperclip-1.8.0-py3.6.egg-info folder from C:\Program Files\Python36. And it solved my problem thank you guys

I had the same issue but realized this later...what I figured out was that pip was installing the module into the site-packages folder in the AppData\Roaming location instead of the AppData\Local folder. Once I moved the module's folders into the right spot it worked!
If you also run into this issue, maybe just do a quick check that pip is installing where you want it to. Now to figure out how to change the default install path...

How to properly install matplotlib on mac 10.7.5? And why is the command "conda" not found after Anaconda is successfully installed?

I tried for a long time to work with python on this Mac. I tried to remove python completely from my mac. Then I realized it was hard to get rid of this default python. Fortunately, I read in the internet that it's a bad idea to remove that one python that come with Mac before I figured out how to remove it. Then I also installed python, numpy, scipy, matplotlib using *.dmg packages. After all the effort, I still get this error message every time I import pylab. Please help me? Anyone?
$python
Python 2.7.4 (v2.7.4:026ee0057e2d, Apr 6 2013, 11:43:10)
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import pylab
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/Library/Python/2.7/site-packages/matplotlib-1.1.0-py2.7-macosx-10.7-intel.egg/pylab.py", line 1, in <module>
from matplotlib.pylab import *
File "/Library/Python/2.7/site-packages/matplotlib-1.1.0-py2.7-macosx-10.7-intel.egg/matplotlib/pylab.py", line 221, in <module>
`from matplotlib import mpl # pulls in most modules
File "/Library/Python/2.7/site-packages/matplotlib-1.1.0-py2.7-macosx-10.7-intel.egg/matplotlib/mpl.py", line 2, in <module>
`from matplotlib import axis
File "/Library/Python/2.7/site-packages/matplotlib-1.1.0-py2.7-macosx-10.7-intel.egg/matplotlib/axis.py", line 14, in <module>
`import matplotlib.text as mtext
File "/Library/Python/2.7/site-packages/matplotlib-1.1.0-py2.7-macosx-10.7-intel.egg/matplotlib/text.py", line 31, in <module>
`from matplotlib.backend_bases import RendererBase
File "/Library/Python/2.7/site-packages/matplotlib-1.1.0-py2.7-macosx-10.7-intel.egg/matplotlib/backend_bases.py", line 48, in <module>
`import matplotlib.textpath as textpath
File "/Library/Python/2.7/site-packages/matplotlib-1.1.0-py2.7-macosx-10.7-intel.egg/matplotlib/textpath.py", line 9, in <module>
`from matplotlib.mathtext import MathTextParser
File "/Library/Python/2.7/site-packages/matplotlib-1.1.0-py2.7-macosx-10.7-intel.egg/matplotlib/mathtext.py", line 52, in <module>
`import matplotlib._png as _png
ImportError: dlopen(/Library/Python/2.7/site-packages/matplotlib-1.1.0-py2.7-macosx-10.7-intel.egg/matplotlib/_png.so, 2): Library not loaded: /opt/local/lib/libpng14.14.dylib
Referenced from: /Library/Python/2.7/site-packages/matplotlib-1.1.0-py2.7-macosx-10.7-intel.egg/matplotlib/_png.so
Reason: image not found
Besides, I followed the instruction on http://ipython.org/install.html to install Anaconda. After Anaconda is installed I went to the next step
$ conda update conda
and got this
"-bash: conda: command not found"
I searched in the net, but it seems no one else has this problem. Can anyone give me a hint here? Many thanks!
In my directory /usr/bin I have
python python-config python2.5 python2.5-config python2.6 python2.6-config python2.7 python2.7-config
With command
which python
I got /Library/Frameworks/Python.framework/Versions/2.7/bin/python
with
which ipython
I got /Library/Frameworks/Python.framework/Versions/2.7/bin/ipython
For numpy I downloaded the package numpy-1.7.0-py2.7-python.org-macosx10.6.dmg, scipy-0.12.0-py2.7-python.org-macosx10.6.dmg for scipy, and matplotlib-1.2.0-py2.7-python.org-macosx10.6.dmg for matplotbib.I downloaded *10.6.dmg because that's what I found...I can not find something like *10.7.dmg
I don't have .bashrc or .bashrc_profile. But I think .profile will do, and it reads like this
# MacPorts Installer addition on 2012-03-07_at_18:55:26: adding an appropriate PATH variable for use with MacPorts.
export PATH=/opt/local/bin:/opt/local/sbin:$PATH
# Finished adapting your PATH environment variable for use with MacPorts.
export TERM="xterm-color"
alias ls="ls -G"
export PS1="[\[\e[33m\]\u#\H \[\e[32m\]\w\[\e[0m\]]\n[\[\e[31m\]\!\[\e[0m\]] > "
# Setting PATH for Python 2.7
# The orginal version is saved in .profile.pysave
PATH="/Library/Frameworks/Python.framework/Versions/2.7/bin:${PATH}"
export PATH
When I type in
$port
it says -bash: port: command not found
Should that worry me?
Shall I also out comment the line
export PATH=/opt/local/bin:/opt/local/sbin:$PATH
as well?

You appear to have MacPorts. Perhaps you can use MacPorts to install the Python of your choice, and then use the corresponding pip (probably /opt/local/bin/pip to install the necessary Python packages.
If MacPorts is something you're not using anymore, I suggest to use homebrew instead: http://mxcl.github.io/homebrew/ . Pay attention to the message you get after installing Python: it tells you that some Python scripts will be installed in /usr/local/share/python. In your case, this may not be an issue (the packages you listed don't install Python scripts afaik).
Keep in mind that using homebrew and MacPorts together may still mess with Python and its packages.
Finally, you need to make sure you don't keep on using the other python executable. Therefore, in your .profile, comment out the last two lines like this:
#PATH="/Library/Frameworks/Python.framework/Versions/2.7/bin:${PATH}"
#export PATH
Update
Then, to get rid of the MacPorts reference and ensure your PATH picks up /usr/local/bin, change your .profile further to
# MacPorts Installer addition on 2012-03-07_at_18:55:26: adding an appropriate PATH variable for use with MacPorts.
#export PATH=/opt/local/bin:/opt/local/sbin:$PATH # <- comment out
# Set /usr/local/bin explicitly for Homebrew
export PATH=/usr/local/bin:$PATH
Start in a new Terminal (or tab) to have your settings updated.

Python: No module named contextlib?

Does anyone know where i can find this python module 'contextlib'?
root#overo:~# python
Python 2.6.6 (r266:84292, Mar 9 2011, 10:05:36)
[GCC 4.3.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import contextlib
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named contextlib
I did not compile python myself personally. I'm just in this mess. It's running on an ARM based CPU so maybe some things were left out to save space.
I ran find / | grep contextlib which resulted in nothing.
Can i download this module from somewhere and just plonk it in /usr/lib/python2.6? Will that work?

I got this error in a different way.
I created a pipenv virtual environment using the 32bit version of Python 3.6.5 on Windows 10. I then realized I needed the 64bit version. Uninstalled the 32bit, installed the 64bit, and then tried to go back to my existing virtual env. The previously created env was now broken in odd ways and gave me this error.
I solved this by removing the old pipenv pipenv --rm and creating a new one with the newly installed version of python.

As others have noted, that module should be in the standard library, but if it's an embedded device, it may have been dropped to save space (if true, a foolish choice IMO, since leaving out contextlib.contextmanager robs the with statement of much of its power and convenience)
If you can name the specific device or manufacturer (or ask the vendor directly), you may be able to get a better answer.
As far as fixing it goes, grabbing http://hg.python.org/cpython/file/2.6/Lib/contextlib.py and dropping it in sys.path somewhere should do the trick (running python -m site will dump the list of directories that you can use)

It has been part of the standard library since 2.5 according to the docs. It seems a bit weird that you don't have it, it works with 2.6.6 for me (Ubuntu 10.10):
blair#blair-eeepc:~$ python
Python 2.6.6 (r266:84292, Sep 15 2010, 15:52:39)
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import contextlib
>>> contextlib.__file__
'/usr/lib/python2.6/contextlib.pyc'
Somebody may have a better suggestion, but if it comes to it there is a link at the top of the documentation to the source code (which is Python, so you should be able to use it directly without any compilation or anything).
Edit: Unless, as Santiago Lezica suggested, you compiled your copy of Python manually, in which case it should be a simple matter of copying the module into the correct library path.
Edit for updated question: To the best of my knowledge, just dropping the source into a directory on the Python path should work. You could do this in the system library, but, to avoid it being deleted/replaced/otherwise borked in future updates, I'd recommend putting it in a separate directory and adding that directory to the Python path. You could put it under /usr/local, or somewhere in your home directory.

With Angsrom Linux, contextlib is included in the python-misc package. You can grab it by running:
opkg install python-misc
This won't, however, get you all expected python modules, so you may also want to install python-modules:
opkg install python-modules

I found one more occasion, which produces the same error.
I had made a virtual environment with python 3.6. After a updated my python version to 3.7 I tried to activate the old virtual environment and got this error.
The solution was to delete the old environment and recreate it with the new python version.

Check sys.path to make sure your python interpreter is looking in the right directories. It should look something like this (not necessarily identical):
>>> import sys
>>> sys.path
['', '/usr/lib/python2.6', '/usr/lib/python2.6/plat-linux2', '/usr/lib/python2.6/lib-tk', '/usr/lib/python2.6/lib-old', '/usr/lib/python2.6/lib-dynload', '/usr/local/lib/python2.6/dist-packages', '/usr/lib/python2.6/dist-packages', '/usr/lib/python2.6/dist-packages/PIL', '/usr/lib/pymodules/python2.6']
EDIT: With the updated information in the question that this is an install of unknown origin on a constrained device, assuming that unnecessary modules were removed to save space makes sense. However, for the record, I'll mention another, perhaps more common scenario where modules cannot be found: when there are file permissions issues. For example:
$ python -c 'import contextlib; print(contextlib.__file__)'
/usr/lib/python2.6/contextlib.pyc
$ ls -l /usr/lib/python2.6/contextlib.py*
-rw-r--r-- 1 root root 4136 Dec 26 16:42 /usr/lib/python2.6/contextlib.py
-rw-r--r-- 1 root root 4127 Jan 1 21:45 /usr/lib/python2.6/contextlib.pyc
$ sudo chmod go-r /usr/lib/python2.6/contextlib.py*
$ python -c 'import contextlib; print(contextlib.__file__)'
Traceback (most recent call last):
File "<string>", line 1, in <module>
ImportError: No module named contextlib
Especially with custom installations, import problems due to file permission issues and path problems are some of the easiest things to check and, usually, to fix.

Python 2
sudo apt-get install python-contextlib2
Python 3
sudo apt-get install python3-contextlib2

contextlib was introduced in Python 2.5, can you remove and re-install your Python 2.6.6 again? From my copy of Python 2.6.6:
Python 2.6.6 (r266:84292, Sep 15 2010, 15:52:39)
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import contextlib
>>>