~$ python
bash: python: command not found
while running python2 and python 3 its showing different versions.
~$ python2
Python 2.7.6 (default, Jun 22 2015, 17:58:13)
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
~$ python3
Python 3.4.0 (default, Jun 19 2015, 14:20:21)
[GCC 4.8.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
i think somehow default python link is broken. i can't seem to access ubuntu software center also.
Please suggest a way to fix this.
Rather than re-creating the simlink as suggested, I would start working with virtualenv. You can create virtual environment pointing at different python versions by doing:
virtualenv -p /usr/bin/python2 venv_name (for Python 2.7)
virtualenv -p /usr/bin/python3 venv_name (for Python 3)
Once you go into the venv and do the source venv_name/bin/activate, your python symbolic link will be pointed at the version you've chosen when creating it.
Also, you might find a pyvenv link which will be associated to Python 3 as this version of Python comes with virtualenv (and pip) out of the box. You might need to install virtualenv with pip (or easy install), and to figure it out which Pythonversion is your pip associated to, you can do pip --version
Related
Yesterday, I did put my laptop on upgrade 19.10 to 20.04 but due to power failure, that became a partial-upgrade, the system broked. I resolved everything but my Django app wasn't running due to PYTHONPPATH so I tried uninstalling python3 and everything got broken. I re-installed that again.
Now when I do python --version I got
bash: python: command not found
whereas python3 --version gives correct answer.
Python 3.8.2
I have python2.7 and python3 both installed. So for now, my Python is not working and also I think I've messed up my PYTHONPATH and I really don't know what I'm going to do now.
My ./~bashrc file looks like below :
# Install Ruby Gems to ~/gems
export GEM_HOME=$HOME/gems
export PATH=$HOME/gems/bin:$PATH
# Install Ruby Gems to ~/gems
export GEM_HOME=$HOME/gems
export PATH=$HOME/gems/bin:$PATH
# Install Ruby Gems to ~/gems
export GEM_HOME="$HOME/gems"
export PATH="$HOME/gems/bin:$PATH"
I'm using Ubuntu 20.04.
Please specify how are you running your project and what exactly is the issue you are facing. May be you can paste the error message you get.
For python command,
In Linux, generally the base commands (like python) without version in it, would actually be pointing the specific (python) version executable through symbolic links (or simply links).
[foo#linuxbox ~]$ ls -l /usr/bin/python
lrwxrwxrwx. 1 root root 16 Feb 9 16:26 /usr/bin/python -> /usr/bin/python3
These links can be created or even edited to our need to point to the version we need. Use the below command to link python to python3. This is equivalent to setting alias for python3 as python but bit more than that as all users/process can run python but in case of alias the tool/user must be running from bash or corresponding shell where alias was created.
sudo ln -f -s /usr/bin/python3 /usr/bin/python
I feel in Ubuntu 20 you have to run command python2 to go into 2.7.* interpreter. python and python3 command both refers to Python3. But anyway your python command should work.
#ideapad:~$ python
Python 3.6.9 (default, Apr 18 2020, 01:56:04)
[GCC 8.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
ideapad:~$ python2
Python 2.7.17 (default, Apr 15 2020, 17:20:14)
[GCC 7.5.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
ideapad:~$ python3
Python 3.6.9 (default, Apr 18 2020, 01:56:04)
[GCC 8.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>
To solve your issue, use an alias. Place command alias python=python3 into ~/.bashrc file, after adding this run source ~/.bashrc.
Other solutions:
run command which python it will reveal the location of installed Python and then try adding the location given by which python command to PYTHONPATH
Reinstall your python - sudo apt install python
On macOS Mojave 10.14.6, have the following versions of python installed:
Python 2.7.16
Python 2.7.16 (default, May 17 2019, 18:32:33)
[GCC 4.2.1 Compatible Apple LLVM 10.0.1 (clang-1001.0.46.4)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
Python 3
Python 3.7.4 (v3.7.4:e09359112e, Jul 8 2019, 14:54:52)
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
Installed AWS CLI using these steps:
curl "https://s3.amazonaws.com/aws-cli/awscli-bundle.zip" -o "awscli-bundle.zip"
unzip awscli-bundle.zip
sudo ./awscli-bundle/install -i /usr/local/aws -b /usr/local/bin/aws
Now, when I test aws from the command line using aws --version
aws-cli/1.16.247 Python/2.7.16 Darwin/18.7.0 botocore/1.12.237
Question(s):
Is this correct?
Is it supposed to be using Python 3.7.4 instead?
If so, how can I switch this over?
By default the installer will use whatever is in your path for python.
If you want to use Python 3, you need to run something like this to run the installer:
sudo /usr/local/bin/python3 awscli-bundle/install -i /usr/local/aws -b /usr/local/bin/aws
Replace /usr/local/bin/python3 with your path for Python 3 if it's different.
All of this said, if you have both Python environments installed, I'm not aware of any reason to prefer one version over the other for the AWS CLI tool.
Here is an extract of my console in a Mac, as you can see the Python on the console is 2.7.15 but on the environment it becomes 2.7.10 which is an older version... any help on why and how to fix it would be most welcomed!
dhcp-18-57:Wakeup6 **jbs$ python**
**Python 2.7.15** (default, May 1 2018, 16:44:14)
[GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.42.1)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
dhcp-18-57:Wakeup6 jbs$ virtualenv env
New python executable in /Users/jbs/PycharmProjects/Wakeup6/env/bin/python
Installing setuptools, pip, wheel...done.
dhcp-18-57:Wakeup6 jbs$ source env/bin/activate
(env) dhcp-18-57:Wakeup6 **jbs$ python**
**Python 2.7.10** (default, Oct 23 2015, 19:19:21)
[GCC 4.2.1 Compatible Apple LLVM 7.0.0 (clang-700.0.59.5)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
If you installed python using Anaconda, then set up a new virtual environment for python 2.7.15 Then following directions in the Anaconda documentation, activate this virtual environment and you should be good to go.
If you didn't use Anaconda, just follow the directions for setting up a virtual environment on a Unix box. Then activate that environment and start working.
You can have multiple versions on your computer. Virtual environments allow you to run the version you want. I have virtual environments for python 2.7.13 and python 3.6.
If this doesn't work please let me know. I'll try to help.
Thank you all for your input. I finally figured out how to solve it. The difficult part was finding out how to locate the place where python 2.7.15 was installed which I'll leave intact in the response since I found it by trial and error looking in other places. I have not found a command that gives you the full path (perhaps an expert can tell us how to go from the laconic which python to the full path).
What I find interesting is that it does not really matter what the console uses when calling virtualenv. What matters is the version of Python used to install virtualenv which is the default version that will be used.
Essentially one has to use the -p option in virtualenv and make sure to find the right location where the desired version of python is.
dhcp-18--41:WakeUp8 jbs$ virtualenv -p /usr/local/Cellar/python#2/2.7.15/bin/python env
Running virtualenv with interpreter /usr/local/Cellar/python#2/2.7.15/bin/python
New python executable in /Users/jbs/PycharmProjects/WakeUp8/env/bin/python2.7
Also creating executable in /Users/jbs/PycharmProjects/WakeUp8/env/bin/python
Installing setuptools, pip, wheel...done.
dhcp-18-189-34-41:WakeUp8 jbs$ python
Python 2.7.15 (default, May 1 2018, 16:44:14)
[GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.42.1)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
dhcp-18--41:WakeUp8 jbs$ pwd
/Users/jbs/PycharmProjects/WakeUp8
dhcp-18-189-34-41:WakeUp8 jbs$ source env/bin/activate
(env) dhcp-18-189-34-41:WakeUp8 jbs$ python
Python 2.7.15 (default, May 1 2018, 16:44:14)
[GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.42.1)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>>
I run into this issue ImportError numpy/core/multiarray.so: undefined symbol: PyUnicodeUCS2_AsASCIIString installing Python in a pyenv-virtualenv environment.
In my case, it happens with the matplotlib package instead of numpy (as in the above question), but it's basically the same issue.
The answer given in that question is a simple:
Rebuild NumPy against a Python built as UCS-4.
I don't know how to do this. In this other question it is said that one has to use:
./configure --enable-unicode=ucs4
but I don't know how to use that command along with pyenv.
This issue is also mentioned in pyenv's repo issue list, and a solution given in a comment. Sadly (for me) I can not understand how to apply the fix explained in said comment.
So my question basically is: how do I build Python as UCS-4 via pyenv?
Installing python with pyenv with ucs2:
$ export PYTHON_CONFIGURE_OPTS=--enable-unicode=ucs2
$ pyenv install -v 2.7.11
...
$ pyenv local 2.7.11
$ pyenv versions
system
* 2.7.11 (set by /home/nwani/.python-version)
$ /home/nwani/.pyenv/shims/python
Python 2.7.11 (default, Aug 13 2016, 13:42:13)
[GCC 4.8.4] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sysconfig
>>> sysconfig.get_config_vars()['CONFIG_ARGS']
"'--prefix=/home/nwani/.pyenv/versions/2.7.11' '--enable-unicode=ucs2' '--libdir=/home/nwani/.pyenv/versions/2.7.11/lib' 'LDFLAGS=-L/home/nwani/.pyenv/versions/2.7.11/lib ' 'CPPFLAGS=-I/home/nwani/.pyenv/versions/2.7.11/include '"
Installing python with pyenv with ucs4:
$ pyenv uninstall 2.7.11
pyenv: remove /home/nwani/.pyenv/versions/2.7.11? y
$ export PYTHON_CONFIGURE_OPTS=--enable-unicode=ucs4
$ pyenv install -v 2.7.11
...
$ pyenv local 2.7.11
$ pyenv versions
system
* 2.7.11 (set by /home/nwani/.python-version)
$ /home/nwani/.pyenv/shims/python
Python 2.7.11 (default, Aug 13 2016, 13:49:09)
[GCC 4.8.4] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import sysconfig
>>> sysconfig.get_config_vars()['CONFIG_ARGS']
"'--prefix=/home/nwani/.pyenv/versions/2.7.11' '--enable-unicode=ucs4' '--libdir=/home/nwani/.pyenv/versions/2.7.11/lib' 'LDFLAGS=-L/home/nwani/.pyenv/versions/2.7.11/lib ' 'CPPFLAGS=-I/home/nwani/.pyenv/versions/2.7.11/include '"
I want to access files and directories which may require root permission from a command line call to a python script using Enthought Canopy Python. However running python as root gives me the system distributed python.
$ python
Enthought Canopy Python 2.7.6 | 64-bit | (default, Sep 15 2014, 17:36:10)
[GCC 4.1.2 20080704 (Red Hat 4.1.2-54)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
$ sudo python
Python 2.7.6 (default, Mar 22 2014, 22:59:56)
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
Same results using default bash terminal (Ubuntu Linux 14.04) and using the canopy command line (Canopy 1.5.2).
I reinstalled Canopy as root (i.e. re-ran the shell script as root) and the same problem still occurs.
Is there an easy way to run Canopy as root? I am not trying to distribute it to a number of users on a system just run a python script on files that need root permissions.
It sounds like sudo is not using your current PATH settings to locate the executable to run. IIRC this is a configuration option for sudo, whether to use a limited default PATH or not.
An easy way to work around this is to specify the full path to the python excutable that you want to execute. For example, if you've activated a Canopy virtual environment, then you can do it like this:
$ sudo $VIRTUAL_ENV/bin/python