I have python 2.7.6 and 3.4 on my mac installed currently. I want to upgrade python2 to python 2.7.8 as I believe it is the more secure. What is the right way to do this? Do I simply download the installer from the website and run it? If so, will my system automatically use 2.7.8 over the previously installed 2.7.6?
Note, the python version 2.7.6 came pre-installed. And I apologize if the question seems redundant. I used to develop blindly without any thought of the versions and packages and made a mess of my projects. So now I try to careful.
pyenv is a simple Python version management. You can find more on pyenv.
Related
I just installed ubuntu 18.04 and I really don't know how does everything work yet. I use the last version of python in my windows system (3.8.1) and would like to use that version as well in ubuntu, but the "pre-installed" version of python is 2.7. Is there a way to uninstall that old version of python instead of changin the alias of the python command to match the version I want to use? Can you do that or does ubuntu need to have that version? If you could help me or explain this to me I would appreciate it.
It's not a good idea to remove Python 2 from your Ubuntu 18.04 because maybe some services or apps are using it (Despite that Python 2 doesn't get support any more)
(In Ubuntu 19.10, we have only Python 3)
The best answer is using Virtual Environments that make an isolate work station for you with any thing you wish, and it doesn't mess with other platforms.
Some services and application in Ubuntu use Python 2.x to run. It is not advisable to remove it. Rather, virtual environments maybe a good practice. There, you can work on Python 3.x, as per your needs, without messing up with the system's dependencies.
In case it is relevant, I am using Ubuntu 16.04 LTS. I went to install some software (Jupyter Notebook) which uses Python, and the recommendation was to either use python3 install if I have Python 3, or python install if I am still using 2.7.
My Ubuntu installation came with both. python --version returns 2.7.12 and python3 --version returns 3.5.2. However I also know that there is currently a Python 3.6 out there, which I installed... but it appears to use its own special reference python3.6 --version which returns 3.6.4, whereas I had expected it to upgrade/replace python3 so doing python3 --version would return 3.6.4, but nope.
I'm not sure what the correct approach is here because apparently I shouldn't be messing with the Python versions that come installed since the OS may rely on them. At the same time it seems strange to install software that calls for Python3 even though it's going to be using 3.5 rather than 3.6.
Am I overthinking this? Is it expected behavior to use python3.6 specifically for 3.6-related features? Or do most people re-alias python3 to redirect to python3.6 instead? What about pip? pip3? Is there a pip3.6? I'm not entirely certain how I should be thinking about all these different Python installations.
You may want to use virtualenv so you can control your python environment, it's good practice. With virtualenv you can specify which version to use and your libraries are installed only for the project that needs it.
You can use python2 and python3 alongside just fine. However, if you want to use different minor versions of the python, for example 3.4 and 3.6, you have to set up virtual environment for each version. Look for the virtualenv or other solution.
I use Python 3.4 as 'python3' in terminal (Python 2.7 as 'python'). I recently installed Python 3.6 with Homebrew, but I cannot seem to replace the 3.4 version under 'python3' with 3.6.
I tried this, but I get an error and "Operation not permitted". I'm figuring I need to change a path somewhere, but I'm not sure which files to change.
EDIT: The answer to this question did not solve my problem, I'm fine keeping the default as it is. It does make me realise that maybe just changing the alias is enough, or it that not the appropriate way to go about this? (e.g. this)
To use your newly installed Python, follow ths link: python homebrew by default
Instead of changing the alias named "python3", you could use a virtualenv, that way, you can choose your Python version:
virtualenv -p python3.6 my_venv
source my_venv/bin/activate
python --version
# -> Python 3.6.1
Why do you use homebrew to install a new version of Python 3? You could have done directly from Mac OS X.
I ended up reinstalling, manually removing/reinstalling versions and packages, and then relinked the alias to the Python version I wanted to use. This setup seems to work for me so far.
Supposedly Python 2.7 is included native to OSX 10.8 and above (if I remember correctly), but I recently installed Python 3.5 to use for projects while I work through UDacity. Lo and behold, the UDacity courses seem to use 2.7 - wups! So instead of trying to uninstall 3.5 (this procedure seemed to scary for neophytes such as myself), I simply installed 2.7 in addition to the recently installed 3.5 and just run the 2.7 IDLE and Shell. Is this ok, or will I run into problems down the road?
I have installed two versions, 2.7, 3.4 and I do not have any problem by now. 3.4 I am using for my work project in eclipse environment, 2.7 for udacity course, like You ;).
As long as you keep your installation folders organized, you should have no issues having both on your computer, besides one thing. The path environment variable for python will determine which version is used by default, so I would say stick to one version, or make sure to make your programs as backwards compatible as possible. I have run into this issue on Windows, since I installed Python 3.4 before 2.7, and therefore to run older code, I have to manually select the python executable. In terms of libraries, I believe that for each python version, the libraries are completely separate, so you should be good there.
As others have said, if the installation directory is different it should be no problem at all.
One thing that'll make your life easier for switching between the two is to use an IDE such as PyCharm, you just have to change a drop down to switch between the two versions.
It should be fine. Its actually pretty common to have multiple Python environments. It helps to prevent dependency conflicts between your projects. That is what is happening when you are using tools like pyenv and virtualenv.
Using tools like pyenv and virtualenv may also help you with the path problems that others mentioned. They have commands to set up the path so that their version of pip, python, etc are used.
Im not sure about OSX, but with windows 10 my environment variables for 2.7 were overwritten with the 3.5 path. Not a tough fix, but a little confusing, since it was months later when I needed 2.7 again.
You can also use Anaconda for maintaining two versions of Python:
Download Anaconda for both Python versions
Open .bashrc
Add the path to new Anaconda you have installed for, e.g.:
export PATH="/home/paras/anaconda3/bin:$PATH"
Now there will be 2 export paths: one for Python 2 and one for Python 3. Comment the one which you don't want.
I have the same problem and it is not necessary to uninstall on version of python. Please take care to not mix them up - When you search them up on the start menu. You can make a desktop shortcut saying 2.6 and 3.5.
Hi
I just want to install mercurial but for all versions it needs python 2.6, I tried to use .rpm file but the only thing I got is lots of lines full of error which tells: need old versions before 2.6 and after 2.5 which is installed on my linux. any help would be appreciated.
Bests
Go to ActiveState and download their versions: https://www.activestate.com/activepython/downloads
It's much easier than using the .rpms.
Which distribution are you using? I would recommend you to upgrade your system to a newer version of your linux distro, whatever it is. Modern Linux distros are using at least python2.6 now.
If you do not want to upgrade your system with various reasons, ActiveState's python version as stated in Jasie's answer is good for your cause. It installs python in your system without breaking anything, just you have to add some lines in your .bashrc to force system find your ActiveState python installation before the system's python.
Another alternative would be installing earlier version of mercurial which supports the python version installed on your system. But I would not recommend you to do so..
Among these, my suggestion is upgrading your system to a merely "up-to-date" version, so that python2.6 or higher is installed on your system.