"yum install package" or "python setup.py install" in CentOS? - python

I was wondering how the above "yum install package" & "python setup.py install" are used differently in CentOS? I used yum install ... all the time. However, when I try to do python setup.py install, I always get: this setup.py file couldn't be found even though its path shows up under echo $PATH, unless I try to use it in its current directory or use the absolute path.

When you type python setup.py install, your shell will check your $PATH for the python command, and run that. Then, python will be examining its arguments, which are setup.py install. It knows that it can be given the name of a script, so it looks for the file called setup.py so it can be run. Python doesn't use your $PATH to find scripts, though, so it should be a real path to a file. If you just give it the name setup.py it will only look in your current directory.
The source directory for a python module should not, ideally, be in your $PATH.
yum install is a command that will go to a package repository, download all the files needed to install something, and then put them in the right place. yum (and equivalents on other distributions, like apt for Debian systems) will also fetch and install any other packages you need, including any that aren't python modules.
Python has a package manager, too. You may also find using pip install modulename or pip install --user modulename (if you don't have administrative rights) easier than downloading and installing the module by hand. You can often get more recent versions of modules this way, as the ones provided by an operating system (through yum) tend to be older, more stable versions. Sometimes the module is not available through yum at all. pip can't install any extra packages that aren't python modules, though.
If you don't have pip already (it comes with Python3, but might need installing separately for Python2, depending on how it was set up), then you can install it by following the instructions here: https://pip.pypa.io/en/stable/installing/

Related

pip3 installs modules to location python3 can't find

I have pip3, installed via the yum install of python3-pip.
I've done a pip3 global install of some modules I need, but python3 can't find them to import. After a little investigation I see that pip3 installed the modules to /usrlib/python3.6/site-packages/pip/_vendor/
The problem is that python3 doesn't seem to know to look at pip/_vendor, it only finds modules directly installed under site-package. If I just copy the modules from .../site-package/pip/_vendor to .../site-package everything works fine.
The issue doesn't appear to be related to file permissions or ability to read the modules.
I'm wondering how I configure either pip to install directly to site-package or python3 to understand how to look in the pip/_vendor location.
I'm configuring this all with ansible and would like as module an option as possible. For instance I could manually use an argument to tell pip3 to install to the folder I want, but I don't want to hardcode the exact site-package directory if I don't have to.
I recommend starting over with pip by downloading and running get-pip.py. This will not only install the latest version of pip, but it will also install packages to a Python-readable location (the version of Python you use to run get-pip.py).
As an aside, I would avoid installing packages system-wide unless there is a specific need for them. At the very least, you should be installing them as a regular user, and even better you should be using a virtualenv.

Install git python library through python regardless of OS

I have developed a tool that my team can use after running the setup.py script. The tool requires this library: https://github.com/c2nes/javalang
How can I make my python setup script install this library on their computer regardless of what OS they are on. They can't run my tool without that library (Some people are on windows, mac, and linux.)
pip can install projects on Github as a dependency too!
All you need to do is, in your requirements.txt, add a line like following:
..
git+https://github.com/c2nes/javalang.git
then install the dependency using:
$ pip install -r requirements.txt
What you are looking for exists on PyPI. Instead of git+https://.. line above, just say: javalang. Oh and BTW, unless they are running old versions of Python, they should already have pip installed. If they don't use your operating systems package manager or get-pip.py as you said.

Installing python packages with no installation directory acces and no pip/easy_install/virtual_env

At work we have python installed, but no additional modules. I want to import some scipy modules but I have no access to the python directory for installation.
Similar questions have been asked on StackOverflow, but the answers always assumed easy install, pip or virtualenv were installed. At my workplace, none of these packages are installed. It's just the plain python installation and nothing else.
Is there still an option for me for installing modules in my local folder and calling them from python? If so, how do I go about it?
Not exactly installing modules on your local folder, but a solution nonetheless:
I used to work for a company that used windows and didn't have admin access, so I ended up using Portable python.
It seems portable python is no longer mantained, but you can see some other portable python solutions on their site, most of which you can run straight from your usb.
You can download pip from here http://pip.readthedocs.org/en/stable/installing/ and install it without root privileges by typing:
python get-pip.py --user
This will install to directory with prefix $HOME/.local so the pip executable will be in the directory $HOME/.local/bin/pip, for your convenience you can add this directory to $PATH by adding to end of .bashrc file this string
export PATH=$HOME/.local/bin/:$PATH
After this you can install any packages by typing
pip install package --user
Or you can alternatively compile the python distribution from source code and install to your home directory to directory $HOME/.local or $HOME/opt or any subfolder of $HOME you prefer, let's call this path $PREFIX. For doing this you have to download python source code from official site, unpack it and then run
./configure --prefix=$PREFIX --enable-shared
make install
And then add python binary to $PATH, python libraries to $LD_LIBRARY_PATH, by adding to the end of $HOME/.bashrc file whit strings
export PATH=$PREFIX/bin:$PATH
export LD_LIBRARY_PATH=$PREFIX/lib
and when after restarting bash you can also run
python get-pip.py
and pip and will be installed automatically to your $PREFIX directory. And all other packages those you will install with pip will be automatically installed also to $PREFIX directory. This way is more involved, but it allows you to have the last version of python.

Can I have my pip user-installed package be preferred over system?

I would like to figure out a "fool-proof" installation instruction to put in the README of a Python project, call it footools, such that other people in our group can install the newest SVN version of it on their laptops and their server accounts.
The problem is getting the user-installed libs to be used by Python when they call the scripts installed by pip. E.g., we're using a server that has an old version of footools in /opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/.
If I do python2.7 setup.py install --user and run the main entry script, it uses the files in /Users/unhammer/Library/Python/2.7/lib/python/site-packages/. This is what I want, but setup.py alone doesn't install dependencies.
If I (revert the installation and) instead do pip-2.7 install --user . and run the main entry script, it uses the old files in /opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/ – that's not what I want.
If I (revert the installation and) instead do pip-2.7 install --user -e . and run the main entry script, it uses the files in . – that's not what I want, the user should be able to remove the source dir (and be able to svn up without that affecting their install).
I could use (and recommend other people to use) python2.7 setup.py install --user – but then they have to first do
pip-2.7 install -U --user -r requirements.txt -e .
pip-2.7 uninstall -y footools
in order to get the dependencies installed (since pip has no install --only-deps option). That's rather verbose though.
What is setup.py doing that pip is not doing here?
(Edited to make it clear I'm looking for simpler+safer installation instructions.)
Install virtualenvwrapper. I allows setting up separate python environments to alleviate any conflicts you might be having. Here is a tutorial for installing and using virtualenv.
Related:
https://virtualenvwrapper.readthedocs.org/en/latest/
Console scripts generated by pip in the process of installation should use user installed versions of libraries as according to PEP 370:
The user site directory is added before the system site directories
but after Python's search paths and PYTHONPATH. This setup allows the
user to install a different version of a package than the system
administrator but it prevents the user from accidently overwriting a
stdlib module. Stdlib modules can still be overwritten with
PYTHONPATH.
Sidenote
Setuptools use hack by inserting code in easy_install.pth file which is placed in site-packages directory. This code makes packages installed with setuptools come before other packages in sys.path so they shadow other packages with the same name. This is referred to as sys.path modification in the table comparing setuptools and pip. This is the reason console scripts use user installed libraries when you install with setup.py install instead of using pip.
Taking all of the above into account the reason for what you observe might be caused by:
PYTHONPATH pointing to directories with system-wide installed libraries
Having system-wide libraries installed using sudo python.py install (...)
Having OS influence sys.path construction in some way
In the first case either clearing PYTHONPATH or adding path to user installed library to the beginning of PYTHONPATH should help.
In the second case uninstalling system-wide libraries and installing them with distro package manager instead might help (please note that you never should use sudo with pip or setup.py to install Python packages).
In the third case it's necessary to find out how does OS influence sys.path construction and if there's some way of placing user installed libraries before system ones.
You might be interested in reading issue pip list reports wrong version of package installed both in system site and user site where I asked basically the same question as you:
Does it mean that having system wide Python packages installed with easy_install thus having them use sys.path manipulation breaks scripts from user bin directory? If so is there any workaround?
Last resort solution would be to manually place directory/directories with user installed libraries in the beginning of sys.path from your scripts before importing these libraries.
Having said that if your users do not need direct access to source code I would propose packaging your app together with all dependencies using tool like pex or Platter into self-contained bundle.

Install a Python package into a different directory using pip?

I know the obvious answer is to use virtualenv and virtualenvwrapper, but for various reasons I can't/don't want to do that.
So how do I modify the command
pip install package_name
to make pip install the package somewhere other than the default site-packages?
The --target switch is the thing you're looking for:
pip install --target=d:\somewhere\other\than\the\default package_name
But you still need to add d:\somewhere\other\than\the\default to PYTHONPATH to actually use them from that location.
-t, --target <dir>
Install packages into <dir>. By default this will not replace existing files/folders in <dir>.
Use --upgrade to replace existing packages in <dir> with new versions.
Upgrade pip if target switch is not available:
On Linux or OS X:
pip install -U pip
On Windows (this works around an issue):
python -m pip install -U pip
Use:
pip install --install-option="--prefix=$PREFIX_PATH" package_name
You might also want to use --ignore-installed to force all dependencies to be reinstalled using this new prefix. You can use --install-option to multiple times to add any of the options you can use with python setup.py install (--prefix is probably what you want, but there are a bunch more options you could use).
Instead of the --target or --install-options options, I have found that setting the PYTHONUSERBASE environment variable works well (from discussion on a bug regarding this very thing):
PYTHONUSERBASE=/path/to/install/to pip install --user
(Or set the PYTHONUSERBASE directory in your environment before running the command, using export PYTHONUSERBASE=/path/to/install/to)
This uses the very useful --user option but tells it to make the bin, lib, share and other directories you'd expect under a custom prefix rather than $HOME/.local.
Then you can add this to your PATH, PYTHONPATH and other variables as you would a normal installation directory.
Note that you may also need to specify the --upgrade and --ignore-installed options if any packages upon which this depends require newer versions to be installed in the PYTHONUSERBASE directory, to override the system-provided versions.
A full example
PYTHONUSERBASE=/opt/mysterypackage-1.0/python-deps pip install --user --upgrade numpy scipy
..to install the scipy and numpy package most recent versions into a directory which you can then include in your PYTHONPATH like so (using bash and for python 2.6 on CentOS 6 for this example):
export PYTHONPATH=/opt/mysterypackage-1.0/python-deps/lib64/python2.6/site-packages:$PYTHONPATH
export PATH=/opt/mysterypackage-1.0/python-deps/bin:$PATH
Using virtualenv is still a better and neater solution!
To pip install a library exactly where I wanted it, I navigated to the location I wanted the directory with the terminal then used
pip install mylibraryName -t .
the logic of which I took from this page: https://cloud.google.com/appengine/docs/python/googlecloudstorageclient/download
Installing a Python package often only includes some pure Python files. If the package includes data, scripts and or executables, these are installed in different directories from the pure Python files.
Assuming your package has no data/scripts/executables, and that you want your Python files to go into /python/packages/package_name (and not some subdirectory a few levels below /python/packages as when using --prefix), you can use the one time command:
pip install --install-option="--install-purelib=/python/packages" package_name
If you want all (or most) of your packages to go there, you can edit your ~/.pip/pip.conf to include:
[install]
install-option=--install-purelib=/python/packages
That way you can't forget about having to specify it again and again.
Any excecutables/data/scripts included in the package will still go to their default places unless you specify addition install options (--prefix/--install-data/--install-scripts, etc., for details look at the custom installation options).
Tested these options with python3.5 and pip 9.0.3:
pip install --target /myfolder [packages]
Installs ALL packages including dependencies under /myfolder. Does not take into account that dependent packages are already installed elsewhere in Python. You will find packages from /myfolder/[package_name]. In case you have multiple Python versions, this doesn't take that into account (no Python version in package folder name).
pip install --prefix /myfolder [packages]
Checks if dependencies are already installed. Will install packages into /myfolder/lib/python3.5/site-packages/[packages]
pip install --root /myfolder [packages]
Checks dependencies like --prefix but install location will be /myfolder/usr/local/lib/python3.5/site-packages/[package_name].
pip install --user [packages]
Will install packages into $HOME:
/home/[USER]/.local/lib/python3.5/site-packages
Python searches automatically from this .local path so you don't need to put it to your PYTHONPATH.
=> In most of the cases --user is the best option to use.
In case home folder can't be used because of some reason then --prefix.
pip3 install "package_name" -t "target_dir"
source - https://pip.pypa.io/en/stable/reference/pip_install/
-t switch = target
Nobody seems to have mentioned the -t option but that the easiest:
pip install -t <direct directory> <package>
pip install packageName -t pathOfDirectory
or
pip install packageName --target pathOfDirectorty
Just add one point to #Ian Bicking's answer:
Using the --user option to specify the installed directory also work if one wants to install some Python package into one's home directory (without sudo user right) on remote server.
E.g.,
pip install --user python-memcached
The command will install the package into one of the directories that listed in your PYTHONPATH.
Newer versions of pip (8 or later) can directly use the --prefix option:
pip install --prefix=$PREFIX_PATH package_name
where $PREFIX_PATH is the installation prefix where lib, bin and other top-level folders are placed.
To add to the already good advice, as I had an issue installing IPython when I didn't have write permissions to /usr/local.
pip uses distutils to do its install and this thread discusses how that can cause a problem as it relies on the sys.prefix setting.
My issue happened when the IPython install tried to write to '/usr/local/share/man/man1' with Permission denied. As the install failed it didn't seem to write the IPython files in the bin directory.
Using "--user" worked and the files were written to ~/.local. Adding ~/.local/bin to the $PATH meant I could use "ipython" from there.
However I'm trying to install this for a number of users and had been given write permission to the /usr/local/lib/python2.7 directory. I created a "bin" directory under there and set directives for distutils:
vim ~/.pydistutils.cfg
[install]
install-data=/usr/local/lib/python2.7
install-scripts=/usr/local/lib/python2.7/bin
then (-I is used to force the install despite previous failures/.local install):
pip install -I ipython
Then I added /usr/local/lib/python2.7/bin to $PATH.
I thought I'd include this in case anyone else has similar issues on a machine they don't have sudo access to.
If you are using brew with python, unfortunately, pip/pip3 ships with very limited options. You do not have --install-option, --target, --user options as mentioned above.
Note on pip install --user
The normal pip install --user is disabled for brewed Python. This is because of a bug in distutils, because Homebrew writes a distutils.cfg which sets the package prefix.
A possible workaround (which puts executable scripts in ~/Library/Python/./bin) is:
python -m pip install --user --install-option="--prefix=" <package-name>
You might find this line very cumbersome. I suggest use pyenv for management.
If you are using
brew upgrade python python3
Ironically you are actually downgrade pip functionality.
(I post this answer, simply because pip in my mac osx does not have --target option, and I have spent hours fixing it)
With pip v1.5.6 on Python v2.7.3 (GNU/Linux), option --root allows to specify a global installation prefix, (apparently) irrespective of specific package's options. Try f.i.,
$ pip install --root=/alternative/prefix/path package_name
I suggest to follow the documentation and create ~/.pip/pip.conf file. Note in the documentation there are missing specified header directory, which leads to following error:
error: install-base or install-platbase supplied, but installation scheme is incomplete
The full working content of conf file is:
[install]
install-base=$HOME
install-purelib=python/lib
install-platlib=python/lib.$PLAT
install-scripts=python/scripts
install-headers=python/include
install-data=python/data
Unfortunatelly I can install, but when try to uninstall pip tells me there is no such package for uninstallation process.... so something is still wrong but the package goes to its predefined location.
pip install /path/to/package/
is now possible.
The difference with this and using the -e or --editable flag is that -e links to where the package is saved (i.e. your downloads folder), rather than installing it into your python path.
This means if you delete/move the package to another folder, you won't be able to use it.
system` option, that will install pip package-bins to /usr/local/bin thats accessible to all users. Installing without this option may not work for all users as things go to user specific dir like $HOME/.local/bin and then it is user specific install which has to be repeated for all users, also there can be path issues if not set for users, then bins won't work. So if you are looking for all users - yu need to have sudo access:
sudo su -
python3 -m pip install --system <module>
logout
log back in
which <module-bin> --> it should be installed on /usr/local/bin/
Sometimes it works only works with Cache argument
-m pip install -U pip --target=C:\xxx\python\lib\site-packages Pillow --cache-dir C:\tmp

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