Develop Reference

Waitress installed via pip, but cannot be executed

Overall, pip is working fine on my server. I have just installed the package waitress and the installation seems successful. I checked it with pip freeze:
$ pip freeze | grep waitress
waitress==2.1.0
Waitress also can be imported via python3:
>>> import waitress
>>>
However, waitress-serve cannot be executed:
$ waitress-serve
Command 'waitress-serve' not found, but can be installed with:
apt install python3-waitress
Please ask your administrator.
I am not a root user on this server. Could this be a reason why the package was installed partially, or am I speculating here?
Since I am not authorized to run apt install and since the simple pip install worked in my virtualenv, I would like to be able to get this to work without using the suggested apt install python3-waitress command.

The conclusion is that, while it is installed both inside and outside virtualenv, it is only actually executable inside it.
When installable Python packages give you an actual entry point, generally it will not be on your path.
When you use a virtual environment, activating the environment puts various parts of that environment onto the path temporarily. This is intended to ensure that commands like python or python3 run the environment's Python, but it also allows those entry points to be found on the path.
A system Python installation (here I mean, not just a Python that comes with your operating system, but also one that you install manually after the fact - but not a virtual environment) will generally not have its library folders on the path by default - only enough to make python and pip work. (On Windows, often even these are not added to the path; instead, a program py is placed in the Windows installation folder, and it does the work of looking for Python executables.) Even if you are allowed to install things directly into a system Python (and you should normally not do this if you can avoid it, even if you're allowed to), they won't be findable there.
Of course, you could execute these things just fine by explicitly specifying their paths. However, the normally correct approach is to just ensure that, when you want to run the program, the same virtual environment is activated into which you installed the package.
(On my system, I have one main "sandbox" virtual environment that I use for all my projects - unless I am specifically testing the installation process, or testing how the code works on a different version of Python. Then I use a wrapper script to open a terminal window, navigate to a folder that contains all my projects, and activate the environment.)

if waitress is installed inside a virtual environment, I think you may have accidentally (or not) gotten out of said virtual environment.
If you are running a virtual environment, you can try the following commands, one after the other:
source venv/bin/activate #venv is assumed to be the name of the virtual environment you are using.
pip install waitress
waitress-serve
anytime you need to use waitress you will need to activate the virtual environment yet again:
source venv/bin/activate
waitress-serve
Please take note I am assuming you are running in a Linux environment
If this is not the issue you are facing, then feel free to expaund a bit more on your question.
Edit: Installing with pip and running it worked perfectly on my virtualenv; see the picture below, running on python 3.8.10

'robot is not recognized as an internal or external command'

Problem: I am trying to running my Dummy.robot test script in the terminal via cmd line: robot -d results tests/dummy.robot. However, it is returning the error 'robot' is not recognized as an internal or external command. I sensed that perhaps the robotframework was not properly installed or in the correct directory because the keywords "Open Browser" (see below) was already detected as invalid syntax prior to running.
Troubleshooting Methods:
Checked that both robotframework and robotframework-seleniumlibarary were installed
Installed intellibot on PyCharm and restarted IDE
Made sure I provided the correct path to the script within my project directory as shown below.
Checked that Python 39 and Python39/Scripts was added to my PATH although I am not sure if this is relevant because it just allows me to use pip for installing robotframework later.
Selected the interpreter for this "dummy" project from where that python.exe is located.
Source Screenshots:
File Structure
Run Config & Updated File Structure (3/8/21)
Source Code
Terminal
RF Library Location

I think, going by your terminal pic, it looks like you have a virtual environment: (base). As #TodorMinakov suggested, fire the command pip list in your terminal path (same path as shown in the pic). If Robot Framework libs exist there, then it should be fine. Then try the command python -m robot -d results tests/dummy.robot But if libs are not in the folder, then you have to do pip install for them from Terminal for right installation (which means, your installed libs are in your native directory while you are working in virtual env).
Since you are working with Pycharm IDE, it is better if you could use its terminal instead of using a command line tool such as bash or command prompt. Try this too.
To check if the libs installed are in System Python, you have to go to your folder site packages (eg: C://Python39/Lib/site-packages), you would find all the natively installed libraries here. In case of virtual environment, you have to check in your present directory (where the code exists). There should be a folder by the name venv (or 'base'), which will comprise of the python paths eg: (venv/Lib/site-packages)

I have experienced the same issue and it was a pip versioning issue. It got resolved after installing the upgraded pip version and then reinstalling the robot framework and Appium library. Thanks

Use the terminal in Admin mode.
pip uninstall robotframework
upgrade pip
again pip install robotframework

Question about pip using Python from Windows Store

I have python installed through windows store and I can install programs using pip, but when I try to run said programs, they fail to execute in powershell.
How can I make sure that the necessary "scripts" folder is in my path? I never faced these problems when installing from executable.
For example, "pip install ntfy" runs successfully in Powershell.
The command "ntfy send test" fails telling me the term is not part of a cmdlet, function, etc. etc.
The 'ntfy' program is located here /mnt/c/Users/vlouvet/AppData/Local/Packages/PythonSoftwareFoundation.Python.3.7_qbz5n2kfra8p0/LocalCache/local-packages/Python37/Scripts/ntfy.exe
What is the recommended way of editing my path so that programs installed via pip are available across windows store updates of the Python language?

In advance
I highly recommend you not to use python installed from the Windows Store, because you'll face such errors, and even more nasty ones.
The easy solution
Create a virtual environment on a more accessible folder, for example in C:\Users\<user>\python. To do so, do the following:
Using PowerShell, go to your user folder, using cd(Note that usually PowerShell already starts inside your user folder. This is an important setting to have, and if not, you should change your powershell starting point to this folder for the future.);
Now that you're in your user folder, type in the PowerShell mkdir python; cd python;
Now, to create a virtual environment, type python -m venv venv;
(You can verify that your virtual enviroment has been created by listing the folders, with the command ls);
You have created a virtual environment. Now, you need to activate it. To activate, run the following: ./venv/Scripts/activate;
Now, you have fully created and activated a virtual environment for your current PowerShell session. You can now install any packages / programs using pip.
After that, the only thing that you need to do is to add C:\Users\<user>\python\venv\Scripts to your Path, and you're good to go.
Caveats
By adding this folder to your Path, you may be using an outdated python version in the future, since the Scripts folder inside your virtual environment also adds a python executable that will be enabled in the path.
The recommended solution
As I stated before, I do not recommend to have the Microsoft Store version of python installed on your machine. That said, you're probably using it for the conveniences of having the latest Python version installed as soon as they're released. To alleviate this need while also getting rid of your MS Store Python. I recommend you using Chocolatey to install python (and pretty much any other programs for development).
What is Chocolatey?
Chocolatey is a package manager for Windows, pretty much like apt-get for Ubuntu Linux or HomeBrew for MacOS. By using a package manager, you get rid of the hassle of always having to execute the (mostly annoying) install wizards on windows.
To install Chocolatey:
Go to chocolatey.org/install and follow the install instructions;
(Recommended: Take a look on their documentation later to see what Chocolatey is capable of);
With Chocolatey installed, take a test drive and see if it is working properly by running choco -v in PowerShell;
By having Chocolatey installed, you can now run choco install python -y. Let's break down this command:
choco install -> The package installer of chocolatey
python -> the name of the package you want to install
-y -> This tells the installer to skip install verification by saying "Yes to All" scripts that will be executed in order to install a package.
With python installed from chocolatey, you can also see that Python is already added to your path - This means that any python package or executable installed globally will be now available on your machine!
Hope I could help you!

The above answer is good but I managed to get it to work by doing the following.
Find your installation under C:\Users\"your user"\AppData\Local\Packages it will be named something like PythonSoftwareFoundation.Python.3.7_qbz5n2kfra8p0
Open your windows settings in the start menu
In search type Environment variables. Edit environment variables for your account should pop up. Click it
In the top box find Path, click it
On the right Click new and enter C:\Users\"your user"\AppData\Local\Packages\"python install directory name from 1. here"\LocalCache\local-packages\Python37\Scripts inside the little box under the last item in the list
open a new cmd prompt and type the script you wanted it should work.

On Windows you can find the user base binary directory by running
python -m site --user-site
and replacing site-packages with Scripts.
For example, this could return
C:\Users\Username\AppData\Roaming\Python36\site-packages
so you would need to set your PATH to include
C:\Users\Username\AppData\Roaming\Python36\Scripts
You can set your user PATH permanently in the Control Panel. You may need to log out for the PATH changes to take effect.

VSCode: There is no Pip installer available in the selected environment

I'm trying to run the autopep8 linter on a Python file in VSCode.
I've followed the instructions here: https://code.visualstudio.com/docs/python/environments and selected my interpreter (⇧⌘P): /usr/local/bin/python
I then try to format my code, and VSCode says autopep8 isn't installed, and can be installed via Pip. However, when I try to install via Pip, it says There is no Pip installer available in the selected environment.
I then tried launching a terminal in the current environment by selecting Python: Create Terminal from the Command Palette.
The terminal opens fine, pip is present, and I'm even able to pip install autopep8 in the terminal that opened in VSCode, but when I try running the Format Document command I get the same errors that autopep8 and pip aren't available in the environment.

On Ubuntu16.04, I worked with Python3 in vscode and
apt-get install python3-pip
solves my problem.
That's because I discover that: Under my terminal, I type the pip -V. It displays it's for Python2, not for Python3.

Man you can only change the interpreter.
Go in (ctrl + shift + p), then type Python: Select Interpreter, this way you choose the version that your extension needs.
This worked for me.

I have multiple python versions:
2.7
3.6
3.7
Tell the vscode/ visual studio code, which version to use:
press the following (Show All Commands): Ctrl + Shift + P
paste the following: Python: Select Interpreter
Select one of the version that it shows, I have selected python 3.7.3 64-bit
Update python path in settings:
press Ctrl + , to open Settings
search for python.pythonPath
change python to /usr/bin/python3.7
Note: this may not be needed, however, make sure /usr/bin/python3.7 really exists for you, you may have at a different path like /usr/local/bin/python3.7, etc.
I had pip but it was 2.7, but since I am choosing python 3, it's pip needs to be installed
Run the following command in Terminal: apt-get install python3-pip
Restart vscode
With the above steps, all issues got resolved. Hope that helps.

try Ctrl+Shift+P
then type
Python: Select Interpreter
and select the python version.

Installing python3-pip fixed the issue for me.
apt-get install python3-pip

1.Select the File > Preferences > Settings command (⌘,) to open your User Settings.
2.Search and Create or modify an entry for python.pythonPath with the full path to the Python executable according to your requirements.For Example i changed it to python2.6 path to this path /usr/local/bin/python3.

I had the same problem today, none of the solutions helped me. Eventually, I figured it out myself.
I'm posting this answer for people who are having this problem. Just go to your ./venv folder and you will find a .cfg file.
Just make sure include-system-site-packages is set to true
home = /usr/bin
include-system-site-packages = true
version = 3.8.5
If it still doesn't work, just run sudo install python3-pip once in the terminal. Of course you could always change the version here as well.

(on mac)if you are using python3 but vscode told you pip was not installed , you could change python version on vscode bottom.
And I guess you are using another terminal but not bash , vscode's default terminal is bash. Bash don't know you have install pip#2.

For WSL users:
If you have your work files in linux subsystem path, you still need pip for windows in order to VSCode to use it.

On Ubuntu:
Make sure, that you have Python and pip installed.
Go to Settings, type python.py in search input. This should find Python Path settings.
Remove this path (if it is currently setted), save. Exit Code and set this to current value.
For me is /usr/bin/python3

Had this issue when trying use autopep8. For me - it had nothing to do with pip (I know it is installed) but the path the VScode python extension was using.
If you open up the extension and go to it's setting and scroll down, there is a path you can designate for autopep8: Python › Formatting: Autopep8 Path
I used the path recommended by these docs:
https://code.visualstudio.com/docs/python/editing#_formatting
Which was: python.formatting.autopep8Args
I stopped getting the error.

For Windows system check the environment variable>System variables
check the Path variable for the python path.(if not found set the path variable for python)
Copy the path and paste under vscode>file>preferences>settings>python.pythonPath
It worked for me.

I ran into this problem while learning django and the terminal would not let me pip install anything.
Create a virtual environment in shell and then use the path of the environment as your interpreter. This worked for me.
Note: You might want to create to create the environment in a different shell altogether and then upload the folder of the environment into vscode.
Then you open up the settings file in the environment folder.
This image will hopefully give you a good idea. Click Here

I was having a similar problem with pylint in a docker container. I realized that the reason the VS-Code-prompted pylint install didn't work for me was because I was using the global python installation (global inside my docker container, anyway), which can require elevated permissions to install things and VS code wasn't running as root in the container. According to the vs code python extension docs:
Note: If you're using a global environment and VS Code is not running elevated, linter installation may fail. In that case, either run VS Code elevated, or manually run the Python package manager to install the linter at an elevated command prompt for the same environment: for example sudo pip3 install pylint (macOS/Linux) or pip install pylint (Windows, at an elevated prompt)

Go in (ctrl + shift + p), then type Python: Select Interpreter,
then type Python: Select Interpreter and then click on "Enter interpreter path"
Then click on "Find.. Browse your file. "
Then type Python in c drive search bar and click on latest version of python in case if you have multiple version of python. Enter and modify wait for sometimes to complete then close.
After that restart your vs code.
It worked for me it will work for you also.

Note: This is a solution for Windows.
First make Sure your Python is installed properly. Run the following command:
py --version
If the Previous command is running fine it will give you your python version. In that case go ahead and check if pip is present or not. Run the below command to check:
py -m pip
If pip is present in your system it show give you a list of option and info. If that's the case then go Ahead and run pip. All you need to do is precede the command you would normally write with py -m. For example:
pip install flask
py -m pip install flask
This should solve your problem.

Django-admin creates wrong django version inside virtualenv

I've created a n new directory, a virtualenv and installed a django-toolbelt inside it. The django-version should be 1.8 but when I call 'django-admin.py version' it says 1.6. So when I start a new project it creates a 1.6. I thought virtualenv was supposed to prevent this. What am I doing wrong?
Edit: I think it has to do with the PATH (?). Like it's calling the wrong django-admin version. I'm on Windows 7. Still don't know how to fix it.

I came across this problem too. In the official document, I found that, in a virtual environment, if you use the command 'django-admin', it would search from PATH usually in '/usr/local/bin'(Linux) to find 'django-admin.py' which is a symlink to another version of django. This is the reason of what happened finally.
So there are two methods to solve this problem:
re-symlink your current version django-admin(site-packages/django/bin/django-admin.py) to 'usr/local/bin/django-admin' or 'usr/local/bin/django-admin.py'
REMIND: This is a kind of global way so that it will effects your other django projects, so I recommend the second method
cd to your_virtual_env/lib/python3.x/site-packages/django/bin/(of course you should activate your virtual environment), and then use 'python django-admin.py startproject project_name project_full_path' to create django project

Try and install Django into the virtual environment as well:
pip install django
It should install the latest version, you can also specify a particular version (let's say 1.8.2) if you need to:
pip install django==1.8.2
Either way you'll have the correct version of Django in your virtual environment and it should work as you expect then.
You can also use the following command to see what version you have installed:
pip show django
Update:
It seems that you have the correct version installed in your virtual environment, but for some reason your Windows 7 use the system Django installation instead while you use manage.py or django-admin.py directly. However, you can use python manage.py or python django-admin.py instead, which seems to work as expected (and use the virtualenv Django installation).

I had the same problem. Could be related to your zsh/bash settings.
I realized that using zsh (my default) I would get django-admin version 1.11 despite the Django version was 2.1! When I tried the same thing with bash I would get django-admin version 2.1 (the correct version). Certainly a misconfiguration.
So, I strongly suggest you check your zsh or bash settings to check for paths you might have.

Create a virtual environment for a project:
$ mkdir cd my_project_folder
$ cd my_project_folder
$ virtualenv venv
$ source venv/bin/activate
And now install django
(venv) ~$ pip install django==1.8
manage.py runserver in virtualenv using wrong django version
pip / virtualenv / django installation issue