Develop Reference

Cannot install pip in python 3 mac OSX Big Sur

I recently installed Python 3 and when I wanted to check the version, it says it is Python 2.7
As I understand it, the new MacOS comes with Python 2.7 so that seems to not be the issue.
So when I want to install pip it keeps saying
command not found
How do I install pip then? Help me please

Try the following command:
pip3 install package-name
If you still get the same error message, refer to the following link to get detailed instructions on pip installation on macOS:
https://www.geeksforgeeks.org/how-to-install-pip-in-macos/

I had almost the same problem, what I did was to install Homebrew first.
$ /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"
then add it to the path
after that you can install Python 3 by typing the following command :
$ brew install python
to check if Python3 has been installed type :
$ python3 --version

I would get in the habit of using a virtual environment for every project. Treat the stock system installations as an implementation detail of the OS, not something you should be modifying directly.
You can start with something as simple as
# Ignore the system-installed Python 2
python3 -mvenv venv
. venv/bin/activate
Now python and pip will each refer to the correct versions found in the virtual environment.

Getting error "/usr/bin/python3.9: bad interpreter: No such file or directory" after installing pip in ubuntu 16.04

I installed python3.9 in ubuntu and also make it default which creates some problems. So I again make python 3.5 as default and removed python 3.9.
Then I tried to install pip by using command:
sudo apt-get install python3-pip
and it installed successfully but when I ran:
pip3 --version
it gives me this error:
/usr/bin/python3.9: bad interpreter: No such file or directory
I don't know why I removed python 3.9 completely with all its dependencies then why pip is not installing properly?
Please help me out here i'm really stuck.

This answer might help, you can run pip as a module, try python3 -m pip [commands] to see if it works.

Try running:
pip --version
It might work.

Are pip and python consistent? Seems like the answer is no. Can someone help me decrypt the documentation?

So i'm trying to implement stripe on a Django app and i'm having issues.
I installed Stripe using pip3 -install stripe and it downloaded. However when I run the server it says
ModuleNotFoundError: No module named 'stripe'
So looking around and on this I think I found some sort of an answer.
https://nomodulenamed.com/a/I-have-installed-the-package-using-pip#fail-to-install
Are pip and python consistent?
Seems like the answer is no.
pip3 -V returned pip 20.0.2 from /usr/local/lib/python3.7/site-packages/pip (python 3.7)
and
python3 -V returned Python 3.8.2
It seems that the easy fix is using python3 -m pip3 -V but that returns No module named pip3
and
python3 -m pip -V returns pip 20.1 from /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/pip (python 3.8)
but pip -V returns zsh: command not found: pip
which leaves me quite confused
more over i'm suppose to do # install your package
python -m pip <your-package-name>
so what goes in the place of
<your-package-name>
and I'm I suppose to use pip of pip3 since I use pip3 to install thing.

Since you can have more than one Python2 installation and more than one Python3 installation available on your machine, your question is better answered by understanding virtual environments.
It is precisely the reason why virtual environments exist!
when you create a python3 virtual environment there is no need to call pip3 as it is the default pip.
start by creating your virtual env (Assuming you have virtualenv installed ... if not install it on linux ubuntu by calling
sudo apt-get install virtualenv
sudo apt-get install python3-pip
python3 -m venv env
source bin/env/activate
pip install <yourpackage>
but I believe you are on macOS since you are getting zsh error,
fix your installation by using homebrew
brew install python3
pip3 install virtualenv
virtualenv -p python3 <path-to your-project>
source <path-to your-project>/bin/activate

How to override the pip command to Python3.x instead of Python2.7?

I am using OSX and I have pip installed for both Python3.5 and Python2.7. I know I can run the command pip2 to use Python2 and when I use the command pip3 Python3.x will be used.
The problem is that the default of pip is set to Python2.7 and I want it to be Python3.x.
How can I change that?
edit:
No, I am not running a virtual environment yet. If it was a virtual environment I could just run Python3.x and forget all about Python2.7, unfortunately since OSX requires Python2.7 for it's use I can't do that. Hence why I'm asking this.
Thanks for the answer. I however don't want to change what running python does. Instead I would like to change the path that running pip takes. At the moment pip -V shows me pip 8.1.2 from /Library/Python/2.7/site-packages (python 2.7), but I am looking for pip 8.1.2 from /Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages (python 3.5) I am sure there has to be a way to do this. Any ideas?

Run this:
pip3 install --upgrade --force pip
or even more explicit:
python3 -m pip install --upgrade --force pip
This will install pip for Python 3 and make Python 3 version of pip default.
Validate with:
pip -V

I always just run it via Python itself, this way:
python3 -m pip install some_module
or
python2 -m pip install some_module
The -m calls the __main__.py module of a specified package. Pip supports this.

Can't you alias pip='pip3' in your ~/.bash_profile?
In Terminal, run nano ~/.bash_profile, then add a line to the end that reads alias pip='pip3'. This is safe; it won't affect system processes, only your terminal.

For your projects, you should be using a virtualenv.
You can choose which python will be that of the virtualenv at creation time, by specifying it on the command line:
virtualenv -p python3 env
# then
. env/bin/activate
python # ← will run python3
That python interpreter will be the one used when you run python or pip while the virtualenv is active.
Under the hood, activating the virtualenv will:
modify your PATH environment setting so binaries in env/bin
override those from your system.
modify your PYTHONHOME
environment setting so python modules are loaded from env/lib.
So python, pip and any other package you install with pip will be run from the virtualenv, with the python version you chose and the package versions you installed in the virtualenv.
Other than this, running python without using virtualenv will just run the default python of the system, which you cannot usually change as it would break a lot of system scripts.

It works for me:
As super-user
Uninstall pip
sudo pip uninstall pip
Install pip
sudo python3 -m pip install --upgrade --force pip
Check install path
sudo pip -V
As local-user
Uninstall pip
pip uninstall pip
Install pip
python3 -m pip install --upgrade --force pip
Check install path
pip -V

Although PEP 394 does not specifically mention pip, it does discuss a number of other Python-related commands (including python itself). The short version is that, for reasons of backwards compatibility, the unversioned commands should refer to Python 2.x for the immediate future on most reasonable systems.
Generally, these aliases are implemented as symbolic links, and you can just flip the symlink to point at the version you want (e.g. with ln -f -s $(which pip3) $(which pip) as root). But it may not be a good idea if you have any software that expects to interact with Python 2 (which may be more than you think since a lot of software interacts with Python).
The saner option is to set up a Virtualenv with Python 3. Then, within the Virtualenv, all Python-related commands will refer to 3.x instead of 2.x. This will not break the system, unlike the previous paragraph which could well break things.

Since you have specified in the comments you want syntax like pip install [package] to work, here is a solution:
Install setuptools for Python3: apt-get install python3-setuptools
Now pip for Python3 could be installed by: python3 -m easy_install pip
Now you can use pip with the specific version of Python to
install package for Python 3 by: pip-3.2 install [package]

Why not just repoint the link /bin/python to python3? It seems like the easiest solution. Especially if you want it for all users of your system.

Pip suddenly using wrong version of Python

Having a weird problem with pip on os x.
As far as I can recall (and a quick look at my .bash_history seems to confirm) I have not made any recent changes to my configuration. Alas, the pip command seems to be suddenly using a different version of python than it was previously. Up until now I was using the command pip to manage my python2 libraries and pip3 to manage by python3 libraries. Suddenly, any attempts at running pip install fails with errors like missing parenthesis around print statements.
Here is the result of a few commands I attempted to figure out the problem:
which pip > /usr/local/bin/pip
which pip3 > /usr/local/bin/pip3
which python > /usr/local/bin/python
python version > Python 2.7.11
pip --version > pip 8.1.1 from /usr/local/lib/python3.5/site-packages (python 3.5)
So for some reason the pip command seems to be running from the PyPi2 database but in python3 now? Any ideas how to fix this?

I run with multiple Python versions and thus multiple pip versions as well.
Everytime, however, you update pip, you'll replace the standard pip command with the version you updated. So even pip3 install --upgrade pip will put a /usr/local/bin/pip in your system, messing up the Python 2 version.
Instead, I run pip as an (executable) module:
python3 -m pip search <package>
or
python2 -m pip search <package>
or even
python3.5 -m pip search <package>
This guarantees that your pip version always matches the Python version you want to use it for. It's somewhat longer to type, but I prefer the expliciteness of it (which, I guess, follows the Zen of Python).
Note that updating pip:
python3.5 -m pip install --upgrade pip
will still install a Python 3.5 version in /usr/local/bin/pip, but I'm simply ignoring that. Just beware of (shell) scripts that execute pip directly.

Find absolute path to Python you'd like to use:
which python
Open your default pip executable script:
vi $(which pip)
You will see a shebang line at the top which may point to wrong Python (i had that once too).
Point to the Python you want (see step 1), e.g.:
#!/usr/local/bin/python3.7

Try setting aliases by running the following commands in Terminal,
alias pip="/usr/local/bin/pip"
alias pip2="/usr/local/bin/pip"
alias pip3="/usr/local/bin/pip3"
If this solves your problem then you need to add the aliases in your bash profile.
Look How do I create a Bash alias? for more info.
Alternatively, you have to reinstall pip using python2 get-pip.py first and then python3 get-pip.py get-pip.py can be downloaded here https://bootstrap.pypa.io/get-pip.py

I had exactly the same problem!
I reinstall python2 by brew brew reinstall python#2
after reinstall, pip install packagename works!

None of these worked for me so what I did was navigate to
C:\Users(User)\AppData\Local\Programs\Python\
and deleted all the old python versions I wasn't using. (Worked)