To get straight to the point. MAMP decided to change my python path, for some reason I do not understand. I only noticed this after 20 minutes of annoyance. But that is not my question. My question is how to change this back to my default python install path.
Chriss-MacBook-Pro:~ chrisburgin$ which python
/Applications/MAMP/Library/bin/python
I had to comment out my MAMP stuff inside my .zshrc and then $ source ~/.zshrc and then when I typed $ which python it now pointed to: /usr/bin/python
Related
I have installed Anaconda 2 & 3 in my system. Anaconda 2 contains python 2.7 & Anaconda 3 contains python 3.6.
I need to run my python code using command prompt & I need to use python 3.6
While I'm running python --version, I'm getting python 2.7.14. How do I change it to python 3.6?
As you can see, I have both Python2 and Python3 installed.
I hope you know that the path of the python executable has to be added to the PATH environment variable in Windows. As you can see, the path of Python2 is placed above the path of Python3 in my system.
How does the cmd run commands?
It searches for an executable with the same name in the directory the cmd has been opened in, then goes and searches for the command in the locations provided in the Windows PATH variable, from TOP to BOTTOM.
Which means, it gets the path to Python2 before it can get to the path of Python3. Therefore, every time you type python in your cmd, it runs Python2.
Both Python2 and Python3 executables have the same name in Windows so it never runs python3.
What seems like an obvious solution?
You might think, changing the name of python.exe to python3.exe for the Python3 executable will solve your problem. You are partially right, it will work. But you have to use python3 file.py or python3 --version, which I think, is understandable. But, pip will no longer work if you change the name of the original python executable. You will no longer be able to install external packages and modules.
How can this problem be solved?
You can create an alias for the Python3 executable called python3.bat.
.exe and .bat files can be called from the cmd directly without using their extension. We always write python filename.py instead of python.exe filename.py although both are correct. The same can be done with .bat files.
Go back to the first image and notice the python3.bat file below python.exe. That is my way of calling python3 without renaming my original python executable.
python3.bat
Create a new file using notepad or something and paste this %~dp0python %*
I don't fully understand how this works except that dp0 basically runs python from inside the same directory and %* passes all the arguments to the python executable. Place this file inside your Python3 installation directory and your problem will hopefully be solved.
python3 basically runs your python3.bat file, which in turn runs the python.exe from its folder and passes the arguments to it.
I hope this solves your problem.
You should have python3 also in your path. You could use python3 to run your script:
python3 <your_script>
But to answer your question, you could use alias and update it as python.
$ python --version
Python 2.7.6
$ alias python=python3
$ python --version
Python 3.6.4
If you want to run Python 3.6, then execute python3.6.
Otherwise, check with which python where the symbolic link to the actual python executable is. On my system, it's
/usr/bin/python
and when I ls -la /usr/bin/python, it gives
lrwxrwxrwx 42 user user 42 Aug 24 03:45 /usr/bin/python -> python2.7
If you are really sure that you want to do it, you can now just move the old symlink somewhere:
sudo mv /usr/bin/python /usr/bin/old_python
and create a new symlink:
sudo ln -s /usr/bin/python3.6 /usr/bin/python
Now you should get something like:
$ python --version
Python 3.6.5
I don't guarantee that it doesn't break everything in the world, especially if you have some distro that has a package manager that relies on a specific python version under python.
This seemed to work nicely on Linux Mint 18.
I made a small trick to solve this problem. For me
C:\Python27
and
C:\Python27\Scripts
were at the top of the PATH Environment variable list. I simply selected them and clicked on Moved Down to shift them to the end of the list.
Just make sure that your path of Python3 and its Script folder is above Python2 path.
And it solved the problem for me. Hope it would help you too.
Reason :
How does the cmd run commands?
It searches for an executable with the same name in the directory the cmd has been opened in, then goes and searches for the command in the locations provided in the Windows PATH variable, from TOP to BOTTOM. Which means, it gets the path to Python2 before it can get to the path of Python3. Therefore, every time you type python in your cmd, it runs Python2.
Both Python2 and Python3 executables have the same name in Windows so it never runs python3.
reason is taken from the accepted answer to this question.
In order to run your script with python 3 you can use
python3 <path to file>
P.S.: this should be a comment, but I do not have the required reputation. :)
If Anaconda 3's is the only python3 interpreter in the system you can run python3 instead of python in your command line and it should work.
You can alter PATH parameter inverting the positions of both interpreters.
I have two versions of the python which the first path is python 2(I am still working with python 2), but there are some scripts which should use python 3. This is what I have done:
I have create a bat file.
ex:
open Notepad++ and write :
#echo off
set PYTHONPATH=
"%~dpn0.py" %*
save it as 'yourscriptname.cmd'.
before my script(which should use python3) I just run this file in command line and then run my script. it is working.
I've installed python via homebrew. It is located in:
/usr/local/Cellar/python/2.7.13_1
which should be right.
Now I am trying to use this python installation, but "which python" only shows the macOS python installation at "/usr/bin/python". So i am checking the $PATH and I see that everything should be ok.
"echo $PATH" results in this: /usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin
I restarted the terminal window and this occurs every time. I also did the
"brew doctor" and no warnings appeared.
What I am using:
Standard macOS Terminal-App
Has anybody a clue how this problem could be solved?
Update $PATH in your .bashrc file.
Example add the following line in your .bashrc
export PATH=/usr/local/Cellar/python/2.7.13_1/bin:$PATH
Either add the Python Homebrew prefix to your $PATH, like #Zico suggests in his answer, or link the Python executable into /usr/local/bin (which might already be in your path)
You'd do that with
$ brew link python
Good luck :)
Brew create an python2 alias to
/usr/local/Cellar/python/2.7.13_1/Frameworks/Python.framework/Versions/2.7/bin/python2.7
I just created a copy of python2 alias and rename it to python. That solved the problem
I have been trying to install Open CV 3 on my mac using this tutorial but I cannot get past step three.
So after I do
brew install python
I do
nano ~/.bash_profile
And the at the bottom of the script I paste
# Homebrew
export PATH=/usr/local/bin:$PATH
After that I reload the file like this
source ~/.bash_profile
Finally I check the python like this
which python
And it prints
/usr/bin/python
instead of
/usr/local/bin/python
I have also tried edited the file in TextEdit but it has the same result.
Am I doing something wrong or is this just a bad tutorial?
Thank You in Advance!
Edit:
# Setting PATH for Python 3.5
# The orginal version is saved in .bash_profile.pysave
PATH="/Library/Frameworks/Python.framework/Versions/3.5/bin:${PATH}"
export PATH
##
# Your previous /Users/UserName/.bash_profile file was backed up as /Users/UserName/.bash_profile.macports-saved_2016-07-26_at_12:50:19
##
# MacPorts Installer addition on 2016-07-26_at_12:50:19: adding an appropriate PATH variable for use with MacPorts.
export PATH="/opt/local/bin:/opt/local/sbin:$PATH"
# Finished adapting your PATH environment variable for use with MacPorts.
# Homebrew
export PATH=/usr/local/bin:$PATH
pydoc3.5
python3
python3-32
python3-config
python3.5
python3.5-32
python3.5-config
python3.5m
python3.5m-config
Is there a
/usr/local/Cellar/python/2.7.12/
directory? (Version number might differ.)
Is there a
/usr/local/bin/python
file?
If the Cellar directory is present, but the file isn't, then Homebrew decided to be careful and not put Python in /usr/local/bin/ immediately.
You could manually do
brew link python
and see if there's now a
/usr/local/bin/python
file.
In your case, it appears you have some files related to Python (they might be from a Python 3 installation, can't tell), such as 2to3. You can safely overwrite them, since Python 2 also has this.
Thus:
brew link --overwrite python
is fine.
Note:
Specific Python versions will always exist as python2.7, python3.5 etc (including the full path as necessary). Thus, even overwriting the python executable is safe (provided it's not the system one in /usr/bin): you should then simply be explicit which python executable to use.
Also, when using a tool like pip, you can make sure you're using the correct version by running it e.g. as
/usr/local/bin/pythnon2.7 -m pip <...>
or whatever python executable you want to install things for.
Okay so one brute force solution could be this one https://stackoverflow.com/a/9821036/128517
But maybe you could check the value of your $PATH after source ~/.bash_profile
typing
> echo $PATH
and see if /usr/local/bin is indeed at the beginning.
if it's not, you might need to check if there's another export before yours or maybe you need to edit .profile instead.
Ok, I hate to start another of seemingly hundreds of other threads about this, but how do I set or tweak the PYTHONPATH? I'm very new to Mac and the only other time I've successfully done this was on Windows using Rapid Enviroment Editor. This looks like a whole different beast. I tried installing Django and it failed to do it for 2.7, while I need 3.4, so the current path must be for 2.7. Running which python in Terminal shows the /usr/bin/python directory, which I then can't cd into, let alone find by browsing. I see that my Python 3.4 directory has the Update Shell Profile file, but it has a lot of limitations. I also see other threads mention PYTHONPATH commands in IDLE and creating one of the bash profile type files for the Terminal. How can I set this and not worry about it anymore until I need to run a different version of Python? I'm on Mac 10.9.2.
"Explain like I'm five".
If you want to install packages for python 3.4 use: pip3 install django
When installing for python 2.7 just use: pip install django
To use python 3.4 type python3 in your shell.
To see where all installations of python are use: which -a python
Depending on how you installed the new versions of python you will see output like:
/usr/local/bin/python
/usr/bin/python
If you wanted to use the python in /usr/local/bin/python you can edit your .bashrc file and add export path="/usr/local/bin:$path".
Save, then type source .bashrc in your shell and when you type which python it will show something like /usr/local/bin/python
Don't screw around too much with different versions of python, you will end up causing yourself a lot of problems.
You should not have to change your PYTHONPATH, just specify which python or pip version you want to use and that will most likely be all you need to do.
To update PYTHONPATH you can run from the terminal:
export PYTHONPATH=$PYTHONPATH:/desired/path/to/add
Then to check the updated PYTHONPATH you can run:
echo $PYTHONPATH
I'm not sure if this completely answers your question, but this is one way to make sure modules are visible to python when you import them.
I stupidly downloaded python 3.2.2 and since then writing 'python' in the terminal yields 'command not found'. Also, when starting the terminal I get this:
Last login: Wed May 2 23:17:28 on ttys001
-bash: export: `folder]:/Library/Frameworks/Python.framework/Versions/2.7/bin:/opt/local/bin:/opt/local/sbin:/usr/local/git/bin:/opt/local/bin:/opt/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/Applications/android-sdk-mac_86/tools:/Applications/android-sdk-mac_86/platform-tools:/usr/local/git/bin:/usr/X11/bin:/usr/local/ant/bin': not a valid identifier
Why the Android SDK folder is there is beyond me. It's all jazzed up. Any ideas how can I remove the offending file, folder or fix his problem? I've checked the System Profiler and python 2.6.1 and 2.7.2.5 shows up.
If the binary was not overridden it's typically located in
/System/Library/Frameworks/Python.framework/Versions/X.X/bin/python
where X.X is your version (probably 2.7) if it's not located there it could be sometimes found in
/Library/Frameworks/Python.framework/Versions/X.X/bin/python
If you find the right binary and can run it, go ahead and start symlinking it where you need to and making the necessary patches. My first piece of advice would be changing your Current to point to the old version.
sudo ln -s /System/Library/Frameworks/Python.framework/Versions/X.X /System/Library/Frameworks/Python.framework/Versions/Current
or
sudo ln -s /Library/Frameworks/Python.framework/Versions/X.X /Library/Frameworks/Python.framework/Versions/Current
Something got messed up in your $PATH. Have a look in ~/.profile, ~/.bashrc, ~/.bash_profile, etc., and look for a line starting with export that doesn't end cleanly.
A very ugly solution to your profile problem since $PATH seems to be very wrong (as was mentioned by blahdiblah)
/bin/cp ~/.profile /tmp/bkup_profile
/bin/cat /tmp/bkup_profile | /usr/bin/grep -v "PATH" > ~/.profile
Open a new terminal and see if you can run commands normally try ls, echo, sudo for example.