Develop Reference

Why cant I import/use installed libraries in Python

I recently downloaded Python 3.10 because I used 3.9. At first, everything worked fine. Sadly, I can't use installed libraries nor use newly downloaded ones, since I deleted Python 3.9. What can I do about this problem?
VSCode gives me this Error message:
Traceback (most recent call last):
File "e:\XXXX\XXXX.py", line 5, in <module>
from playsound import playsound
ModuleNotFoundError: No module named 'playsound'

You can check installed packages using this command:
pip freeze
or
pip list
Uninstall and install using command pip install <package-name>

Cannot uninstall python/pip on raspberry pi 3 b+

I am working on a raspberry pi 3B+. I want to upgrade the python from 2.7 to 3.6.
I downloaded the python 3.6 extracted and made it, However it got installed in the /usr/local/bin.
I tried to make it again this time by specifying ./configure --prefix=/usr prefix however the make gave a traceback error.
I also tried update-alternatives --install /usr/bin/python python /usr/bin/python3.6 2 which helps in changing versions of python.
However, after doing so, my pip is not working now.
I have the following files in /usr/local/bin:pip,pip2.7,pip3,pip3.5,pip3.6.
I tried removing pip so that i can reinstall it using sudo apt-get remove python-pip but it gives the following error:
pi#raspberrypi:/usr/local/bin $ sudo apt-get remove python-pip
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
libpython-all-dev python-all python-all-dev python-keyring
python-keyrings.alt python-secretstorage python-wheel
Use 'sudo apt autoremove' to remove them.
The following packages will be REMOVED:
python-pip
0 upgraded, 0 newly installed, 1 to remove and 6 not upgraded.
1 not fully installed or removed.
After this operation, 671 kB disk space will be freed.
Do you want to continue? [Y/n] y
Traceback (most recent call last):
File "/usr/bin/apt-listchanges", line 29, in <module>
import apt_pkg
ModuleNotFoundError: No module named 'apt_pkg'
(Reading database ... 138007 files and directories currently installed.)
Removing python-pip (9.0.1-2+rpt2) ...
File "/usr/bin/pyclean", line 63
except (IOError, OSError), e:
^
SyntaxError: invalid syntax
dpkg: error processing package python-pip (--remove):
subprocess installed pre-removal script returned error exit status 1
Traceback (most recent call last):
File "/usr/bin/pycompile", line 35, in <module>
from debpython.version import SUPPORTED, debsorted, vrepr, \
File "/usr/share/python/debpython/version.py", line 24, in <module>
from ConfigParser import SafeConfigParser
ModuleNotFoundError: No module named 'ConfigParser'
dpkg: error while cleaning up:
subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
python-pip
E: Sub-process /usr/bin/dpkg returned an error code (1)
which suggests that apt_pkg (or some problem with apt-get).
when i do pip --version , i get:
Traceback (most recent call last):
File "/usr/local/bin/pip", line 6, in <module>
from pkg_resources import load_entry_point
ModuleNotFoundError: No module named 'pkg_resources'
I just want to have python 3.6 and 2.7(since i have already installed libraries on 2.7) with functional pip.

Why don't you install miniconda for ARM and get Python and all important packages at once ?
wget http://repo.continuum.io/miniconda/Miniconda3-latest-Linux-armv7l.sh
sudo md5sum Miniconda3-latest-Linux-armv7l.sh
sudo /bin/bash Miniconda3-latest-Linux-armv7l.sh
sudo reboot -h now

I think you aren't aware that most linux distros come shipped with python2 AND python3. By typing python and pip you will use your operating systems python2 and pip2 version.
What you probably want is using python3 and pip3 instead.
Something like "upgrading" from python2 to python3 is not possible because it's a fundamental difference and they are incompatible. This is why you have both installed.
Uninstalling or upgrading your systems python interpreter is a terrible bad idea, because your system needs them. For professional usage you should think about version control again, but for your first (and second) steps in python it's totally fine to use the preinstalled python interpreter of your OS.
Solutions like pyenv or virtualenv are very powerfull tools, but you probably don't want to start with it.

Python SAML authentication

I'm trying to build a SAML authentication mechanism in Python using the OneLogin module, but I can't even get started. Trying from the example code provided in the docs, I can't even load the package.
This works:
import onelogin
but this gets a ModuleNotFoundError:
>>> from onelogin.saml2.auth import OneLogin_Saml2_Auth
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'onelogin.saml2'

I only managed to get this working on a Linux machine, so hope you're not on windows. Here's what worked for me.
I had to do a seperate install of hte xmlsec-library first:
apt-get install xmlsec1 openssl python-lxml libxmlsec1 libxmlsec1-dev
and then I was able to
pip install python3-saml
and there were no complains anymore.

You need to install Xmlsec first and then python3-saml but if you are on Windows, Xmlsec has some issues but as with python 3.6 and below the problem is solved. Use this link to download the wheel file for your python version https://github.com/mehcode/python-xmlsec/releases
Install the wheel file using
pip install <wheel_file_name>
As with Python 3.7, the only way out is to install xmlsec on a Linux machine as it is not yet supported on Windows.

Cannot import psycopg2 from python3 on fedora 27

I've just upgraded to Fedora 27, and have been unable to get psycopg2 working.
I'd very much appreciate any help anyone can provide.
As a simple test case, I've been executing
>>> import psycopg2
at the interactive shell. This works fine for Python 2.7, but fails for Python 3.x.
With Python 3.4 and 3.5, I get the message:
Traceback (most recent call last):
File "", line 1, in
ImportError: No module named 'psycopg2'
With Python 3.6, I see:
Traceback (most recent call last):
File "", line 1, in
File "/home/jazcap53/.local/lib/python3.6/site-packages/psycopg2/init.py", line 50, in
from psycopg2._psycopg import ( # noqa
ImportError: /home/jazcap53/.local/lib/python3.6/site-packages/psycopg2/.libs/libresolv-2-c4c53def.5.so: symbol __res_maybe_init, version GLIBC_PRIVATE not defined in file libc.so.6 with link time reference
I installed Fedora 27 from DVD-ROM. I find psycopg2 packages located at
/usr/lib64/python2.7/site-packages
and
/home/jazcap53/.local/lib/python3.6/site-packages
My Python packages were all either included with Fedora, or installed via dnf. They are:
python3-3.6.3-2.fc27.x86_64
python35-3.5.4-1.fc27.x86_64
python34-3.4.7-1.fc27.x86_64
python2-2.7.14-2.fc27.x86_64
Some packages I have installed that may be relevant are:
python2-devel-2.7.14-2.fc27.x86_64
python3-devel-3.6.3-2.fc27.x86_64
libpqxx-1:5.0.1-2.f27.x86_64
libpqxx-devel-1:5.0.1-2.f27.x86_64
libgcc-7.2.1-2.fc27.x86_64
postgresql-devel-9.6.6-1.fc27.x86_64
P.S.: If I'm asking this question in the wrong place, please direct me to the right place.
Edit:
I noticed that:
/usr/lib64/python2.7/site-packages/
contains subdirectories
psycopg2 and
psycopg2-2.7.3-py2.7.egg-info
but
/usr/lib64/python3.4/site-packages/ and
/usr/lib64/python3.5/site-packages/
contain nothing related to psycopg2
and
/usr/lib64/python3.6/site-packages/
contains subdirectory
psycopg2-2.7.3-py3.6.egg-info
but not psycopg2 itself

As you may have noticed, each version of Python has its own package hierarchy. So the installation on Python 3.6 will not give you access on 3.4 and 3.5.
With that said, there seems to be some problem with the system's standard lib with Python 3.6. One solution to that could be to install without binaries, like this:
python3.6 -m pip uninstall psycopg2
python3.6 -m pip install --no-binary :all: psycopg2
To install psycopg2 on 3.4 and 3.5 you would run these with or without the --no-binary option:
python3.4 -m pip install psycopg2
python3.5 -m pip install psycopg2

If you have automatic installs / docker install you need to ensure you add the following line to requirements.txt to ensure psycopg2 installs from source, rather than using the binary, or you'll continue to experience the above issue upon deployment.
psycopg2>=2.7,<2.8 --no-binary psycopg2

I'm having troubles getting pybrain working through anaconda

Here is my problem:
After I managed to install anaconda (having python 3.4), I apparently managed to install pybrain too. But when i use 'import pybrain' from anaconda or from the terminal too I get this error:
>>> import pybrain
Traceback (most recent call last):
File "<ipython-input-2-0fb7233d2a8c>", line 1, in <module>
import pybrain
File "//anaconda/lib/python3.4/site-packages/PyBrain-0.3-py3.4.egg/pybrain/__init__.py", line 1, in <module>
from structure.__init__ import *
ImportError: No module named 'structure'

Simply running sudo pip3 install git+https://github.com/pybrain/pybrain.git worked for me after having the same issue.
The version up on PyPi isn't Python 3 compatible.
Installing the latest commit directly using pip3 should take care of your old package (from PyPi) as well.