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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?

jcmiller11
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  • Any chance another program (like an install script) pre-pended something to your `.bashrc` or linked pip to pip3? – ChrisP Mar 30 '16 at 14:17
  • What version of OSX are you running? Where did you get that python from? Homebrew? Are you sure you didn't update something? – djhoese Mar 30 '16 at 14:21
  • That's possible, but I don't see anything in my .bash_profile (and don't have a .bashrc) I run brew update and brew upgrade about daily. OS X version is 10.11.4 – jcmiller11 Mar 30 '16 at 14:21
  • If you are on Mac OS X and update python with brew. It seem to knock out pip. Its has happened more than once for me. – Merlin Jun 03 '16 at 04:48
  • @jcmiller11 please see my answer http://stackoverflow.com/a/37586175/4988742 and let me know if that was the cause. – Dmitry Tokarev Jun 05 '16 at 06:50

6 Answers6

46

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.

  • +1 This is a better solution than worrying about what version of Python pip will try to use implicitly when you have both Python 2 and 3 on a system. Should be the accepted answer imho – pumpkinthehead Dec 06 '19 at 18:34
  • Instead of python3 -m pip search use python3 -m pip install as "pip search" is depreciated. See status.python.org for more information. – Peurke Mar 25 '21 at 21:23
  • @Peurke : Kindly suggest it as an edit, instead of a comment – aspiring1 Aug 15 '21 at 19:55
12

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
Dmitry Tokarev
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  • This did not work for me. pip still had some other internal reference to the wrong python version, fwiw. – BishopZ Nov 27 '18 at 18:13
  • my answer is based on my local setup, i will fix it. @BishopZ first see which pip is your default pip by running: "which pip". To see which python your pip is using run: "head -1 $(which pip)" Also this fix may be invalid since it worked for me in 2016, but pip changed significantly since then. – Dmitry Tokarev Nov 28 '18 at 19:05
  • @BishopZ i just updated the answer, i tested the steps and those are good for recent pip (ver 18.1) and python 3.7 – Dmitry Tokarev Nov 29 '18 at 02:24
  • @DmitryTokarev: But the problem here is like in one of the other answers, now I do `python3.7 -m pip -V`, it will spit out `pip version xx.xx for python 2.7` and hence it has ruined `pip3.7`, which may even be the default `pip3` for a user – aspiring1 Aug 15 '21 at 19:46
  • Also, why not just set update the symlink to `/usr/local/bin/pip`? – aspiring1 Aug 15 '21 at 19:56
4

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

alec_djinn
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4

I had exactly the same problem!

I reinstall python2 by brew brew reinstall python@2

after reinstall, pip install packagename works!

shihs
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    For whatever reason, I had to do `brew uninstall python@2` then `brew install python@2`. reinstall didn't work. – BishopZ Nov 27 '18 at 18:14
0

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)

Majid Hajibaba
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Xpired
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0

My pip also was aimed at the wrong Python (I want 310). Python310 -m pip install wasn't working for me because python310 was not a variable in my environment. Instead I realized I need to write out the path (in my case its C:\Python310\python.exe) and then in command prompt do

PATH -m pip install <package>

which for me is

C:\Python310\python.exe -m pip install <package>

its extra typing, but it works perfectly.

Now need to figure out how to reconfigure my pip to default back to Python310...

Ariel Vardy
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