I'm working on an (Windows and Mac) application that uses Python as an embedded scripting language.
The application includes an internal text editor, implemented using Scintilla, and I'm using Jedi for autocompletion, which generally works great.
However, when attempting autocompletion on a computer that does not have a separate installation of Python, Jedi raises an error:
jedi.api.environment.InvalidPythonEnvironment:
Could not get version information for 'python':
FileNotFoundError(2, 'The system cannot find the file specified', None, 2, None)
Digging into the code, I can see that the underlying code that is throwing the FileNotFoundError is when Jedi attempts to run python using subprocess.Popen. Python is not installed on the computer, so this fails.
I can also reproduce the same issue on a computer that does have Python installed by editing my Path environment variable not to include the location of python.exe.
Ideally, we don't want users of our application to have to install Python just to get autocompletion working.
My questions:
Is it possible to get Jedi not to spawn subprocesses, and instead run its code inside the same instance of Python within which it itself is running? I couldn't find anything about this in the documentation or the source code that deals with Environments, and extrapolating from the discussion here I suspect the answer might be no.
Is it possible somehow to get Jedi to use the same python37.dll that our application is using for its functionality, instead of looking for a .exe file that does not exist?
Is there any way we could make some kind of minimal Python installation within our existing app installation that uses the same DLLs/Python Lib etc? How could I go about doing this?
Is there any other way to get Jedi autocompletion working in our app without requiring the user to install Python, or including a full Python installer as part of our build process?
Is it possible to get Jedi not to spawn subprocesses, and instead run its code inside the same instance of Python within which it itself is running? I couldn't find anything about this in the documentation or the source code that deals with Environments, and extrapolating from the discussion here I suspect the answer might be no.
This is definitely possible. All the tools are there. There are discussions ongoing here: https://github.com/davidhalter/jedi-vim/issues/870.
IMO a patch to Jedi is needed that uses an jedi.api.environment.InterpreterEnvironment in some cases like yours. It's definitely possible, it's just buggy at the moment.
So I wrote a Python script which does some simple stuff. It was originally going to run on a Unix server but due to crappy network security settings which TPTB refuse to change, we need to run it on a Windows server instead. However, the administrators of said Windows server refuse to do anything helpful like install Python.
What are my options for running a Python script on Windows without Python?
Consideration 1:
Something like Py2Exe - I found this after a quick Google search and it seems promising. From what I can tell, it'll generate a bunch of files but we can just xcopy that directory to our Windows machine and it will be completely isolated and not have any external dependencies. Does anyone have any insight on how well this works? Obviously, it depends on my Python script but fortunately this script is quite simple and only uses built in Python libraries such as urllib2 and urlparse.
Consideration 2:
We can assume the Windows server has at least some version of the .NET Framework installed too, which brings IronPython to mind. I've never used this before, but I've always wanted to. From what I can tell, it will compile Python code into CLS compliant IL code which can be run natively under the .NET runtime. However, does this require additional .NET libraries to be installed on the server? Can I just bundle those DLLs with my program? Or, does it require I rewrite my Python script to call into .NET Framework specific classes instead of using things like urllib2 or urlparse?
Thanks!
PS - The ironic part: I actually barely know Python and I'm a .NET expert, but I wrote the script in Python because I was told it would run on a Unix server. Had I known we'd end up running this on a Windows server, I'd have written the thing in C# to begin with in about 1/10th of the time. Fail.
Will they let you copy executables onto the server at all? If so then you should be able to do a non-admin installation of Python or use Portable Python which can just be copied into a folder without any installation at all.
Nothing wrong with Py2exe, but it does mean you then have to build the script into a fresh executable each time you update it. Also Py2exe has a slightly longer startup time than a Python interpreter because it has to extract the Python dlls into a temporary folder each time it runs; that only matters of course if you run your script a lot.
I am used to using PHP and it is easy to set up, I can just run an exe package like Xampp and have apache and PHP running in 5 minutes on my windows system. Is there something similar to Python?
Unlike PHP, Python's primary purpose is a general-purpose tool for running on the desktop/server, not necessarily as a web application. It has bindings to many powerful GUI toolkits (Qt and wx are two examples of free and popular toolkits that work great on Windows), and so on. Therefore you just download it (either from python.org or from activestate), install it, and run it. That's it.
That said, Python is actually great for web apps too. See the Django tutorial for running a simple web-app on your PC in just a few minutes. Python actually comes with a simple web-server built-in, and it supports SQLite out of the box as well, so you can have a fully functional DB-backed web-application running without actually installing anything else. Naturally, if you need to use tools like MySQL and Apache, these are easy to connect to Python on the desktop too. Just start with that Django tutorial and everything will be clear.
Yes, you can find python from http://python.org
and If you like to make executable files from .py source file you may use py2exe
You don't say in your question what you are going to use Python for, so most answers above are completely correct in pointing out that you install Python by downloading it from Python.org. But you seem to expect more. Is it correct to assume you are going to use it to do web development?
In that case, prepare for a shock, because Python doesn't do things like PHP does at all. You want to use a web framework. There are loads of them for Python. Which on to use depends both on what you are going to do, and your personal taste.
The only "Download as one file and install to run" web system I know of that's based on Python is Plone. And Plone is great, but it's not a webframework, it's a content management system. But hey, maybe that's what you want? :-)
The other frameworks are usually easy to install as well.
(In the long run: If you are going to do web development, you'll be happier with something Unix based. Just saying.)
Download python installer and run python.
Nope no easy way out for you yet, Python is obviously not popular enough in Web dev. You should install mod_python and django. There are some nice step here.
Here's my opinionated answer:
Download and install ActivePython
Open Command Prompt and type pypm install django
Follow the Django tutorial
Note that Django does not necessarily require a webserver like Apache, as it already includes one for development purposes. Nor do you necessarily have to install MySQL as Python already includes SQLite which is supported by Django.
I'm a .NET developer who knows very little about Python, but want to give it a test drive for a small project I'm working on.
What tools and packages should I install on my machine? I'm looking for a common, somewhat comprehensive, development environment.
I'll likely run Ubuntu 9.10, but I'm flexible. If Windows is a better option, that's fine too.
Edit: To clarify, I'm not looking for the bare minimum to get a Python program to run. I wouldn't expect a newbie .NET dev to use notepad and a compiler. I'd recommend Visual Studio, NUnit, SQL Server, etc.
Your system already has Python on it. Use the text editor or IDE of your choice; I like vim.
I can't tell you what third-party modules you need without knowing what kind of development you will be doing. Use apt as much as you can to get the libraries.
To speak to your edit:
This isn't minimalistic, like handing a .NET newbie notepad and a compiler: a decent text editor and the stdlib are all you really need to start out. You will likely need third-party libraries to develop whatever kind of applications you are writing, but I cannot think of any third-party modules all Python programmers will really need or want.
Unlke the .NET/Windows programming world, there is no one set of dev tools that stands above all others. Different people use different editors a whole lot. In Python, a module namespace is fully within a single file and project organization is based on the filesystem, so people do not lean on their IDEs as hard. Different projects use different version control software, which has been booming with new faces recently. Most of these are better than TFS and all are 1000 times better than SourceSafe.
When I want an interactive session, I use the vanilla Python interpreter. Various more fancy interpreters exist: bpython, ipython, IDLE. bpython is the least fancy of these and is supposed to be good about not doing weird stuff. ipython and IDLE can lead to strange bugs where code that works in them doens't work in normal Python and vice-versa; I've seen this first hand with IDLE.
For some of the tools you asked about and some others
In .NET you would use NUnit. In Python, use the stdlib unittest module. There are various third-party extensions and test runners, but unittest should suit you okay.
If you really want to look into something beyond this, get unittest2, a backport of the 2.7 version of unittest. It has incorporated all the best things from the third-party tools and is really neat.
In .NET you would use SQL Server. In Python, you may use PostgreSQL, MySQL, sqlite, or some other database. Python specifies a unified API for databases and porting from one to another typically goes pretty smoothly. sqlite is in the stdlib.
There are various Object Relational Models to make using databases more abstracted. SQLAlchemy is the most notable of these.
If you are doing network programming, get Twisted.
If you are doing numerical math, get numpy and scipy.
If you are doing web development, choose a framework. There are about 200000: Pylons, zope, Django, CherryPy, werkzeug...I won't bother starting an argument by recommending one. Most of these will happily work with various servers with a quick setting.
If you want to do GUI development, there are quite a few Python bindings. The stdlib ships with Tk bindings I would not bother with. There are wx bindings (wxpython), GTK+ bindings (pygtk), and two sets of Qt bindings. If you want to do native Windows GUI development, get IronPython and do it in .NET. There are win32 bindings, but they'll make you want to pull your hair out trying to use them directly.
In order to reduce the chance of effecting/hosing the system install of python, I typically install virtualenv on the ubuntu python install. I then create a virtualenv in my home directory so that subsequent packages I install via pip or easy_install do not effect the system installation. And I add the bin from that virtualenv to my path via .bashrc
$ sudo apt-get install python-virtualenv
$ virtualenv --no-site-packages ~/local
$ PATH=~/local/bin:$PATH #<----- add this to .bashrc to make it permanent
$ easy_install virtualenv #<--- so that project environments are based off your local environment rather than the system, probably not necessary
Install your favorite editor, I like emacs + rope, but editors are a personal preference and there are plenty of choices.
When I start a new project/idea I create a new virtual environment for that project, so that I don't effect dependencies anywhere else. Since I would hate for some of my projects to break due to an upgrade of a library both that project and the new one depends on.
~/projects $ virtualenv --no-site-packages my_new_project.env
~/projects/my_new_project.env $ source bin/activate
(my_new_project.env)~/projects/my_new_project.env $ easy_install paste ipython #whatever else I think I need
(my_new_project.env)~/projects/my_new_project.env $ emacs ./ & # start hacking
When creating a new package...in order to have something that will be easy_installable/pippable use paster create
(my_new_project.env)~/projects/my_new_project.env$ paster create new_package
(my_new_project.env)~/projects/my_new_project.env/new_package$ python setup.py develop new_package
That's the common stuff as far as I can think of it. Everything else would be editor/version control tool specific
Since I'm accustomed to Eclipse, I find Eclipse + PyDev convenient for Python. For quick computations, Idle is great.
I've used Python on Windows and on Ubuntu, and Linux is much cleaner.
If you launch a terminal and type python you'll get an interpreter, where you can start trying stuff.
Just in case you haven't seen it, check out the book Dive Into Python, is free on-line.
http://www.diveintopython.org/
Follow the examples in the book using the interpreter.
For storing your work you could use any editor; Vim or EMACS could be the most powerful, but also the most difficult to learn at first. If you want a more "traditional" IDE, you could try WingIDE.
http://www.wingware.com/
After you start to get more comfortable with python you should try an enhanced interpreter; try ipython.
http://ipython.scipy.org/moin/
When you start to develop a more serious project you'll need to get additional modules. Here you have two options; 1) Use your distribution tools to install additional modules; or 2) Download the modules you need directly from their sites and install them manually. You'll be responsible to upgrade them of course.
You'll have to decide for yourself which way to go. Personally I prefer to download and install additional modules manually.
Python (duh), setuptools or pip, virtualenv, and an editor. I suggest geany, but that's just me. And of course, any other Python modules you'll need.
Getting to Python from .NET world
Jumping into the Linux world from a .NET / WIndows background can be a bit disconcerting (but I do encourage you to keep trying Linux)
But I would suggest to anyone coming from Windows, to stick with Windows for a little while. goto www.Activestate.com and download their Python package - it includes the full win32com extentions by Mark Hammond and it also includes a complete, fast IDE "pythonwin"
I have done real professional development with just this setup alone on a windows box - one 14MB .msi and off you go !
Now to use Python on the DLR (Dynamic common language runtime) you need to download IronPython. THis is a seperate interpreter, that was also originally written by Mark Hammond at Microsoft and is at ironpython.org.
With this you can run code like (from wikipedia) ::
import clr
clr.AddReference("System.Windows.Forms")
from System.Windows.Forms import MessageBox
MessageBox.Show("Hello World")
Now you can access any .NET code from python.
If you're just starting out with Python, I'd actually argue against bringing in the complexity of virtualenv (which I think can be pretty overwhelming), at least until you've got a firm grasp of Python basics (especially regarding library/dependency management).
If you're using Ubuntu and the Gnome desktop environment, gedit is the default (gui) text editor, and has great support for Python built in. So my recommendation is to start with the pre-installed Python and gedit (which is pretty extensible on its own).
You don't need much. Python comes with "Batteries Included."
Visual Studio == IDLE. You already have it. If you want more IDE-like environment, install Komodo Edit.
NUnit == unittest. You already have it in the standard library.
SQL Server == sqlite. You already have it in the standard library.
Stop wasting time getting everything ready. It's already there in the basic Python installation.
Get to work.
Linux, BTW, is primarily a development environment. It was designed and built by developers for developers. Windows is an end-user environment which has to be supplemented for development.
Linux was originally focused on developers. All the tools you need are either already there or are part of simple yum or RPM installs.
You would probably like to give NetBeans Python IDE a shot. You can choose to use either Windows/Linux.
Database: sqlite (inbuilt). You might want SQLAlchemy though.
GUI: tcl is inbuilt, but wxPython or pyQt are recommended.
IDE: I use idle (inbuilt) on windows, TextMate on Mac, but you might like PyDev. I've also heard good things about ulipad.
Numerics: numpy.
Fast inline code: lots of options. I like boost weave (part of scipy), but you could look into ctypes (to use dlls), Cython, etc.
Web server: too many options. Django (plus Apache) is the biggest.
Unit testing: inbuilt.
Pyparsing, just because.
BeautifulSoup (or another good HTML parser).
hg, git, or some other nice VC.
Trac, or another bug system.
Oh, and StackOverflow if you have any questions.
Pycharm Community is worth to try.
I'm building a Django app, which I comfortably run (test :)) on a Ubuntu Linux host. I would like to package the app without source code and distribute it to another production machine. Ideally the app could be run by ./runapp command which starts a CherryPy server that runs the python/django code.
I've discovered several ways of doing this:
Distributing the .pyc files only and building and installing all the requirements on target machine.
Using one of the many tools to package Python apps into a distributable package.
I'm really gunning for nr.2 option, I'd like to have my Django app contained, so it's possible to distribute it without needing to install or configure additional things. Searching the interwebs provided me with more questions than answers and a very sour taste that Django packing is an arcane art that everybody knows but nobody speaks about. :)
I've tried Freeze (fails), Cx_freeze (easy install version fails, repository version works, but the app output fails) and red up on dbuilder.py (which is supposed to work but doesn't work really - I guess). If I understand correctly most problems originate form the way that Django imports modules (example) but I have no idea how to solve it.
I'll be more than happy if anyone can provide any pointers or good resources online regarding packing/distributing standalone Django applications.
I suggest you base your distro on setuptools (a tool that enhances the standard Python distro mechanizm distutils).
Using setuptools, you should be able to create a Python egg containing your application. The egg's metadata can contain a list of dependencies that will be automatically installed by easy_install (can include Django + any third-party modules/packages that you use).
setuptools/distutils distros can include scripts that will be installed to /usr/bin, so that's how you can include your runapp script.
If you're not familiar with virtualenv, I suggest you take a look at that as well. It is a way to create isolated Python environments, it will be very useful for testing your distro.
Here's a blog post with some info on virtualenv, as well as a discussion about a couple of other nice to know tools: Tools of the Modern Python Hacker: Virtualenv, Fabric and Pip
The --noreload option will stop Django auto-detecting which modules have changed. I don't know if that will fix it, but it might.
Another option (and it's not ideal) is to obscure some of your core functionality by packaging it as a dll, which your plain text code will call.