Empacotando o Seu Código

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Package your code to share it with other developers. For example,to share a library for other developers to use in their application,or for development tools like ‘py.test’.

An advantage of this method of distribution is its well established ecosystemof tools such as PyPI and pip, which make it easy for other developers todownload and install your package either for casual experiments, or as part oflarge, professional systems.

It is a well-established convention for Python code to be shared this way.If your code isn’t packaged on PyPI, then it will be harderfor other developers to find it and to use it as part of their existingprocess. They will regard such projects with substantial suspicion of beingeither badly managed or abandoned.

The downside of distributing code like this is that it relies on therecipient understanding how to install the required version of Python,and being able and willing to use tools such as pip to install your code’sother dependencies. This is fine when distributing to other developers, butmakes this method unsuitable for distributing applications to end-users.

ThePython Packaging Guideprovides an extensive guide on creating and maintaining Python packages.

Alternatives to Packaging

To distribute applications to end-users, you shouldfreeze your application.

On Linux, you may also want to considercreating a Linux distro package(e.g. a .deb file for Debian or Ubuntu.)

For Python Developers

If you’re writing an open source Python module,PyPI, more properly known asThe Cheeseshop, is the place to host it.

Pip vs. easy_install

Usepip. More detailshere.

Personal PyPI

If you want to install packages from a source other than PyPI (say, ifyour packages areproprietary), you can do it by hosting a simple HTTPserver, running from the directory which holds those packages which need to beinstalled.

Showing an example is always beneficial

For example, if you want to install a package calledMyPackage.tar.gz,and assuming this is your directory structure:

  • archive
    • MyPackage
      • MyPackage.tar.gz

Go to your command prompt and type:

$cd archive$ python -m http.server9000

This runs a simple HTTP server running on port 9000 and will list all packages(likeMyPackage). Now you can installMyPackage using any Pythonpackage installer. Using pip, you would do it like:

$ pip install --extra-index-url=http://127.0.0.1:9000/ MyPackage

Having a folder with the same name as the package name iscrucial here.I got fooled by that, one time. But if you feel that creating a folder calledMyPackage and keepingMyPackage.tar.gz inside that isredundant, you can still install MyPackage using:

$ pip install  http://127.0.0.1:9000/MyPackage.tar.gz

pypiserver

pypiserver is a minimal PyPIcompatible server. It can be used to serve a set of packages to easy_installor pip. It includes helpful features like an administrative command(-U) which will update all its packages to their latest versionsfound on PyPI.

S3-Hosted PyPi

One simple option for a personal PyPI server is to use Amazon S3. Aprerequisite for this is that you have an Amazon AWS account with an S3 bucket.

  1. Install all your requirements from PyPi or another source
  2. Install pip2pi
  • pipinstallgit+https://github.com/wolever/pip2pi.git
  1. Follow pip2pi README for pip2tgz and dir2pi commands
  • pip2tgzpackages/YourPackage (orpip2tgzpackages/-rrequirements.txt)
  • dir2pipackages/
  1. Upload the new files
  • Use a client like Cyberduck to sync the entirepackages folder to your s3 bucket.
  • Make sure you uploadpackages/simple/index.html as well as all new files and directories.
  1. Fix new file permissions
  • By default, when you upload new files to the S3 bucket, they will have the wrong permissions set.
  • Use the Amazon web console to set the READ permission of the files to EVERYONE.
  • If you get HTTP 403 when trying to install a package, make sure you’ve set the permissions correctly.
  1. All done
  • You can now install your package withpipinstall--index-url=http://your-s3-bucket/packages/simple/YourPackage.

For Linux Distributions

Creating a Linux distro package is arguably the “right way” to distribute codeon Linux.

Because a distribution package doesn’t include the Python interpreter, itmakes the download and install about 2-12 MB smaller thanfreezing your application.

Also, if a distribution releases a new security update for Python, then yourapplication will automatically start using that new version of Python.

The bdist_rpm command makesproducing an RPM filefor use by distributions like Red Hat or SuSE trivially easy.

However, creating and maintaining the different configurations required foreach distribution’s format (e.g. .deb for Debian/Ubuntu, .rpm for RedHat/Fedora, etc.) is a fair amount of work. If your code is an application thatyou plan to distribute on other platforms, then you’ll also have to create andmaintain the separate config required to freeze your application for Windowsand OS X. It would be much less work to simply create and maintain a singleconfig for one of the cross platformfreezing tools, which will produce stand-alone executables for alldistributions of Linux, as well as Windows and OS X.

Creating a distribution package is also problematic if your code is for aversion of Python that isn’t currently supported by a distribution.Having to tellsome versions of Ubuntu end-users that they need to addthe‘dead-snakes’ PPAusingsudo apt-repository commands before they can install your .deb filemakes for an extremely hostile user experience. Not only that, but you’d haveto maintain a custom equivalent of these instructions for every distribution,and worse, have your users read, understand, and act on them.

Having said all that, here’s how to do it:

Useful Tools