I'm running macOS 11.2.2 Big Sur and I'm trying to get pip to work with the latest Python 3.9.4. This turned out to be ridiculously difficult even though I've read a number of articles on the subject. Possibly, it is the debris I accumulated in the system over the years which is causing me trouble. I need advice as to how to get things right again.
Checklist:
/usr/local/opt/python/bin/python3 --version is Python 3.9.4 installed from brew in the most usual way; it's a symlink to ../Frameworks/Python.framework/Versions/3.9/bin/python3, which is in Cellar.
Both python and python3 commands are aliased to /usr/local/opt/python/bin/python3, they give the correct version.
I used both get-pip.py and ensurepip, and both of them say everything is fine: "Successfully installed pip-21.1.1 setuptools-56.0.0"
The only thing in env that has anything to do with Python is this part of PATH: /usr/local/opt/python#3.9/Frameworks/Python.framework/Versions/3.9/bin. The lack of this one is reported as warning when you install pip.
Still, I get this:
python -m pip --version
/usr/local/opt/python#3.9/bin/python3.9: No module named pip
What am I missing? 🤯
I also found this article that instructs to use pyenv, but running it on the latest macOS is yet another problem: pyenv install 3.9.4 doesn't build for some reason.
Using pointers from #gold_cy in the comments I was able to resolve the problem by running get-pip.py with an additional parameter: --prefix=/usr/local/.
While the official pip installation guide does mention that there may be problems on the systems like macOS that manage their own Python install, it doesn't say directly what you can do about it. Which is a shame, because the phrasing in PyPA » Python Packaging User Guide » Tutorials » Installing Packages is exactly the same, only the last phrase is missing from pip's page:
Warning Be cautious if you’re using a Python install that’s managed by your
operating system or another package manager. get-pip.py does not coordinate
with those tools, and may leave your system in an inconsistent state. You can
use python get-pip.py --prefix=/usr/local/ to install in /usr/local which is
designed for locally-installed software.
I was trying to resolve the problem for python3 in MacOS. The accepted answer didn't help me.
What helped me is complete reinstall of the python3:
brew uninstall python3 # if python3 worked before
brew install python3
I need to work with Both Python 2.7.12 and python 3.5.2 simultaneously on my Ubuntu 16.04.1 LTS. Python 3 came pre-installed so I've no idea where it sits, in terms of path to the directory, while python 2 sits in /usr/local/lib/python2.7/.
I found lots of questions on SO and on askubuntu about how to install but nothing about how to use them separately, installing different libraries, and what should I avoid or be careful of, if I maintain this dual python thing for the long term? For example, I usually run pip install to install a library and I can check that its installed in my python2 directory but how do I install the same package for my python3 without conflicts? Something like: python3 pip install <package> ?? Where is the default python3 installed? And how do I call python3 for paths where python is not part of the command for example: pip freeze, sudo-apt get, etc.?
PS: I've not officially worked with Virtualenv but I've been informed that is usually good for isolating projects within a python language version, rather than isolating two different language versions from each other.
Please let me know.
Thanks
This is absolutely no problem, as Python does that for you. You don't need a virtualenv at all.
If you use Ubuntu packages, make sure you use the python3- versions for Python 3, and the normal python- versions for Python 2.
For example, python3-numpy and python-numpy.
If you use pip to install extra packages, you an either use the pip script with the version number appended: pip2.7 or pip3.5, or, my preferred method, call pip as a module for the respective Python executable:
python2.7 -m pip install <whatever>
and
python3.5 -m pip install <whatever>
Other than that, there should not be any issue: Python stores the packages in completely separate directories, and each Python executable only uses its respective directive.
Do not fiddle around with PYTHONPATH, unless you really know what you're doing. This has the danger of setting your PYTHONPATH to a directory with Python 2.7 modules and then using Python 3.5 to run things.
If you start from scratch, you may need to install pip first.
For the system Python(s), use the relevant package:
sudo apt install python-pip
sudo apt install python3-pip
For your locally installed Python(s), use the built-in bootstrapper module:
pythonx.y -m ensurepip
Note on the OS-installed Python executables:
Python 3.5 lives at /usr/bin/python3.5, Python 2.7 (the OS one) at /usr/bin/python2.7.
You could even use the OS 2.7 one next to your locally installed /usr/local/bin/python2.7 (and confuse yourself when a package can't be found because you used the wrong one).
Or install Python 3.6 next to Python 3.5 (provided you've used make altinstall, so python3 doesn't get overwritten).
This is also why you don't really want to run pip (or even pip2.7) as is: pip2.7 may get you the system one, instead of the one in /usr/local/bin/pip2.7, depending on your PATH.
(The same goes for the python2.7 executable, so if you need to specify the full path /usr/local/bin/python2.7 to run that one (or have an alias), the same holds for pip2.7. If, on the other hand, /usr/local/bin is first on your PATH, you should in principle never run into the same pip and python executables.)
I'm not overly familiar with Linux and am trying to run a Python script that is dependent upon Python 3.4 as well as pymssql. Both Python 2.7 and 3.4 are installed (usr/local/lib/[PYTHON_VERSION_HERE]). pymssql is also installed, except it's installed in the Python 2.7 directory, not the 3.4 directory. When I run my Python script (python3 myscript.py), I get the following error:
File "myscript.py", line 2, in
import pymssql
ImportError: No module named 'pymssql'
My belief is that I need to install pymssql to the Python 3.4 folder, but that's my uneducated opinion. So my question is this:
How can I get my script to run using Python 3.4 as well as use the pymssql package (sorry, probably wrong term there)?
I've tried many different approaches, broken my Ubuntu install (and subsequently reimaged), and at this point don't know what to do. I am a relative novice, so some of the replies I've seen on the web say to use ENV and separate the versions are really far beyond the scope of my understanding. If I have to go that route, then I will, but if there is another (i.e. easier) way to go here, I'd really appreciate it, as this was supposed to just be a tiny thing I need to take care of but it's tied up 12 hours of my life thus far! Thank you in advance.
It is better if when you run python3.4 you can have modules for that version.
Another way to get the desire modules running is install pip for python 3.4
sudo apt-get install python3-pip
Then install the module you want
python3.4 -m pip install pymssql
The easiest way is to use virtual environments instead of system paths or environment scripts. See official Python package installation guide.
All you need to do is to
# Create fresh Python environemnt
virtualenv -p python3.4 my-venv
# Activate it in current shell
source my-venv/bin/activate
# Install packages
pip install mysqlclent
Note that mysqlclient is Python 3.x compatible version.
I have the requests module installed on my system.
pip install requests
Now I am trying to import requests in the rpel
import requests
It fails with the following error
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named requests
The most common reason for this is that you have two versions of Python 2.x, and the pip that comes first in your PATH doesn't go with the python that comes first in your PATH.
There are two ways that can happen.
First, you may have, e.g., /usr/local/bin before /usr/bin on your PATH, but your /usr/local copy of Python doesn't have pip. So, when you run pip install requests, that's /usr/bin/pip, which installs into /usr/lib/python2.7/site-packages. But when you run python, that's /usr/local/bin/python, which looks in /usr/local/lib/python2.7/site-packages.
Second, even though your two Python 2.x's are in different locations, they may want to install pip (and other scripts and executables) to the same place. In particular, /usr/bin is usually reserved for stuff that comes with the OS or its package manager, so if you use /usr/bin/python ez_setup.py or /usr/bin/easy_install pip or many other common ways to install pip, it may end up in /usr/local/bin. In which case it will overwrite any earlier /usr/local/bin/pip that went with your /usr/local/bin/python. At any rate, the result is basically the same: pip now means /usr/local/bin/pip, but it still goes with your /usr Python, not your /usr/local Python, and installs into /usr/lib/python2.7/site-packages, which /usr/local/bin/python can't see.
If your two versions are, e.g., 2.7 and 3.4, there's no problem; per PEP 394, either the 3.x versions of everything have to be run with python3 and pip3 and so on, or the 2.x versions have to be run with python2 and pip2 and so on.
If your two versions are, e.g., 2.6 and 2.7, there is a problem, but you can easily work around it, because you should always have pip2.6 and python2.6 vs. pip2.7 and python2.7. You can confuse yourself with python and pip, but you don't have to.
If your two versions are both 2.7, however, there's no way to disambiguate (except by using complete absolute paths all the time, which no one wants to do).
So, why would anyone ever install two copies of Python 2 without knowing what they're doing?
The most common reason is that they're on a Mac, which comes with Python 2.7, but they read a blog post that told them to install another Python and didn't explain how to know what they're doing. Apple's pre-installed Python is in /usr/bin but installs scripts and binaries to /usr/local/bin. The most popular alternative Python versions are the python.org installer and Homebrew, both of which install to /usr/local/bin by default. The fact that Mac users tend to be less Unix-savvy than Linux or FreeBSD users probably doesn't help, but even without that, this is a perfect way to end up with thousands of people who have a pip and a python that doesn't match, and no idea why.
There used to be good reasons for almost all Mac Python users to installing a second Python. Until OS X 10.6, Apple's pre-installed Python versions tended to be badly out of date, and sometimes broken. If Apple's only giving you 2.4, it makes sense to install 2.6. And doing so is no problem, because python2.4 and python2.6 are easy to disambiguate. But Apple has been installing a working 2.7 for years now. There are sometimes good reasons why you need a different one (you need a bug fix in 2.7.7 but Apple gave you 2.7.5, you need a 32-bit build, you need an extra-batteries version like Enthought, you need to build py2app bundles out of it, …), but these reasons do not apply to most people anymore.
In fact, many people on StackOverflow seem to have three versions of Python 2.7. I'm not sure why this is so common, but they'll use Homebrew to install Python 2.7, and then use an installer from Python.org or Enthought, and now they've got three Python 2.7 versions all fighting over ownership of /usr/local/bin.
So, how can you fix this?
If you can use Python 3.x, install that and just use pip3 and python3 (and ipython3 and so on), and paths aren't an issue anymore.
If you don't need a second Python 2.7, get rid of the non-Apple one and just use Apple's.
Otherwise, do not ever use Apple's Python, do not install things for it, do not touch it; just leave it alone for Apple's own tools. If you use Homebrew, its Python should be higher on the PATH (make sure you've got /usr/local/bin before /usr/bin), and it should let you pip install foo without sudo, while Apple's won't, which makes it hard to accidentally screw up and install to the wrong one.
I've also seen at least one Windows user who had both C:\Python27 and D:\Python27, both on the PATH, with the C: one first, but pip only installed for D:. This seems to be far less common than the Mac confusion (probably because Windows doesn't come with Python, and there are no package managers, so the only way you're going to get any Python is by running an installer). And the solution is even simpler here: Windows doesn't need Python, so you can delete whichever one you want.
Finally, on non-Mac *nix systems, especially RHEL/CentOS Linux, you may have a Python 2.6 or 2.4 that's needed by the OS plus a Python 2.7 that you installed because you needed it, or a 2.7 that's needed by the OS and a 2.5 installed as a dependency for some "compatibility" package, or similar. Either way, you can easily accidentally install the pip for the one you don't actually use (especially if you install it with the pip bootstrap instead of your package manager).
The solution here is pretty simple: uninstall that pip, and use yum or apt or whatever to install the python-pip that goes with the Python 2.7 you want to use. And get in the habit of using python2.7 and pip2.7—or just add aliases to your profile so that python or py or whatever you prefer runs python2.7.
For devs with similar problem: Intall python3 version directly from the pack file on their website.
DO NOT DELETE OR EDIT ANYTHING ON usr/local/bin !
rm -rf /Library/Frameworks/Python.framework/Versions/2.7
rm -rf "/Applications/Python 2.7"
Install python3 directly from package on official website.
Reopen VSCode, (if you don't use it, you must) re-install modules in "Not Found" state, run command:
pip3 install requests
and other "not found" modules by command pip3 install xxxxxx
Add "python.pythonPath": "/usr/local/bin/python3" to your settings.json file.
pip install request
-bash: pip: command not found
or
no module name requests
how to fix errors
first:
Download the following and install with python http://get-pip.py
https://bootstrap.pypa.io/get-pip.py
[go to the link and download the python script that I provided and then run it or right click and save as]
then after running script "python space (drag and drop the script in terminal)" run "pip install requests" if you get the error below;
-bash: pip: command not found
See the path mentioned in the warning.
then follow this steps acordilly
see the path in yellow?yeah
/Users/macbookair/Library/... etc
type cd in terminal and then drag and drop the bin folder
1.cd /Users/macbookair/Library/Python/2.7/bin {cd /Users/name/path/Python/version/bin )
./pip install requests
after theses steps
Now run your python script again it should work
up vote me if it helped you.
Are you using Linux and have both python2 and python3 installed?
If so, you installation by:
pip install requests
would install the module to python2
So if you run import in python3, it may cause the problem.
Try to call:
pip3 install requests
to install the module in python3 environment.
I am currently trying to run Pydev with Pymongo on an Python3.3 Interpreter.
My problem is, I am not able to get it working :-/
First of all I installed Eclipse with Pydev.
Afterwards I tried installing pip to download my Pymongo-Module.
Problem is: it always installs pip for the default 2.7 Version.
I read that you shouldn't change the default system Interpreter (running on Lubuntu 13.04 32-Bit) so I tried to install a second Python3.3 and run it in an virtual environement, but I can't find any detailed Information on how to use everything on my specific problem.
Maybe there is someone out there, that uses a similar configuration and can help me out to get everything running (in a simple way) ?
Thanks in advance,
Eric
You can install packages for a specific version of Python, all you need to do is specify the version of Python you want use from the command-line; e.g. Python2.7 or Python3.
Examples
Python3 pip your_package
Python3 easy_install your_package.