I read somewhere you could run python without an OS. How would I do this? Would I need to compile it? Can I run it raw? And if I did need to compile it, what tool would I use and what format would I compile it to?
As far as I know there's not really any way to do this easily but I could be wrong. There are "portable" versions of python but these are operating system dependent. I think what you're referencing is some guys at PyCon managed to run python from the GRUB Bootloader. Your best bet would be installing some minimalist Linux distribution, with essentially only Python and some core packages required to run. The problem is that there's a lot of types of hardware out there, all with their own drivers and assembly language. Python can work as a low level language when you need it to but it seems like configuration would be a nightmare. I haven't looked into it super thoroughly but it seems difficult and impractical. Having an OS above python gives you access to the package managers IDEs and compilier options that make python worth using.
yea that's one of the options, pretty much all the "light" distros will be similar, if you want more to try out try here. Not sure why you're worried about speed though, if you're having speed issues it's far more likely to be the IDE you're using or your code bogging down the computer, not any sort of compiler issues.
Related
I'm having some trouble with distributing my python programs. for linux it's easy enough, just tell people which packages they need and provide the source. for windows however it's a different story altogether. I can get my program compiled with py2exe. the problem there however is that it always seems to miss one dll file or the other.
my question therefore is, is there some easy way to package a python script for multiple platforms? right now I keep having to go on a wild goosechase after dll files I don't have. and this isn't even mentioning the 32bit vs. 64bit problem which leaves a lot to desire.
any and all pointers are welcome. the ideal solution would be some sort of script that would create two zipfiles. one being linux/source and one for windows64bit/windows32bit. I really don't care all that much about mac support, but it would be welcome.
If you support linux, you probably support mac in the same way.
I typically use py2exe to distribute to windows, but there are alternatives, such as cxfreeze, and others. I haven't bothered to care much about 64/32 bit and just deliver a 32 bit solution.
Here are a list of packagers:
http://www.freehackers.org/Packaging_a_python_program
Is it possible to deploy python applications such that you don't release the source code and you don't have to be sure the customer has python installed?
I'm thinking maybe there is some installation process that can run a python app from just the .pyc files and a shared library containing the interpreter or something like that?
Basically I'm keen to get the development benefits of a language like Python - high productivity etc. but can't quite see how you could deploy it professionally to a customer where you don't know how there machine is set up and you definitely can't deliver the source.
How do professional software houses developing in python do it (or maybe the answer is that they don't) ?
You protect your source code legally, not technologically. Distributing py files really isn't a big deal. The only technological solution here is not to ship your program (which is really becoming more popular these days, as software is provided over the internet rather than fully installed locally more often.)
If you don't want the user to have to have Python installed but want to run Python programs, you'll have to bundle Python. Your resistance to doing so seems quite odd to me. Java programs have to either bundle or anticipate the JVM's presence. C programs have to either bundle or anticipate libc's presence (usually the latter), etc. There's nothing hacky about using what you need.
Professional Python desktop software bundles Python, either through something like py2exe/cx_Freeze/some in-house thing that does the same thing or through embedding Python (in which case Python comes along as a library rather than an executable). The former approach is usually a lot more powerful and robust.
Yes, it is possible to make installation packages. Look for py2exe, cx_freeze and others.
No, it is not possible to keep the source code completely safe. There are always ways to decompile.
Original source code can trivially be obtained from .pyc files if someone wants to do it. Code obfuscation would make it more difficult to do something with the code.
I am surprised no one mentioned this before now, but Cython seems like a viable solution to this problem. It will take your Python code and transpile it into CPython compatible C code. You also get a small speed boost (~25% last I checked) since it will be compiled to native machine code instead of just Python byte code. You still need to be sure the user has Python installed (either by making it a pre-requisite pushed off onto the user to deal with, or bundling it as part of the installer process). Also, you do need to have at least one small part of your application in pure Python: the hook into the main function.
So you would need something basic like this:
import cython_compiled_module
if __name__ == '__main__':
cython_compiled_module.main()
But this effectively leaks no implementation details. I think using Cython should meet the criteria in the question, but it also introduces the added complexity of compiling in C, which loses some of Python's easy cross-platform nature. Whether that is worth it or not is up to you.
As others stated, even the resulting compiled C code could be decompiled with a little effort, but it is likely much more close to the type of obfuscation you were initially hoping for.
Well, it depends what you want to do. If by "not releasing the source code" you mean "the customer should not be able to access the source code in any way", well, you're fighting a losing battle. Even programs written in C can be reverse engineered, after all. If you're afraid someone will steal from you, make them sign a contract and sue them if there's trouble.
But if you mean "the customer should not care about python files, and not be able to casually access them", you can use a solution like cx_Freeze to turn your Python application into an executable.
Build a web application in python. Then the world can use it via a browser with zero install.
After playing around with NSIS (Nullsoft Scriptable Installation System) for a few days, I really feel the pain it's use brings me. No wonder, the authors claim it's scripting implementation is a "mixture of PHP and Assembly".
So, I hope there is something better to write installation procedures to get Windows programs installed, while creating the installation package on Linux.
But I did not find anything yet. Wix looks promising, but seems not really to run on Linux, Python can create .msi files - but only when running on Windows.
Izpack is out of the game because it requires Java for the installer to run on the target system.
Our app to be installed is a python app (and I'm even thinking about scripting the whole install myself in Python).
Any other ideas?
Forgot to say: Free/OpenSource apps preferred.
Not only because of cost, because of the power to control and adjust everything.
We might be willing to pay professional support if it helps us getting to our goals fast, but we also want to have full control over the build system.
You may be interested by BitRock
You might try looking at InstallAnywhere, but it may require Java.
Try running InnoSetup under Wine. It should work unless you have some very specific needs. InnoSetup is open source, BTW.
It seems that pyinstaller might do the trick. I'm also looking for something like what you need. I have not tried it yet ...
I've got some experience with Bash, which I don't mind, but now that I'm doing a lot of Windows development I'm needing to do basic stuff/write basic scripts using
the Windows command-line language. For some reason said language really irritates me, so I was considering learning Python and using that instead.
Is Python suitable for such things? Moving files around, creating scripts to do things like unzipping a backup and restoring a SQL database, etc.
Python is well suited for these tasks, and I would guess much easier to develop in and debug than Windows batch files.
The question is, I think, how easy and painless it is to ensure that all the computers that you have to run these scripts on, have Python installed.
Summary
Windows: no need to think, use Python.
Unix: quick or run-it-once scripts are for Bash, serious and/or long life time scripts are for Python.
The big talk
In a Windows environment, Python is definitely the best choice since cmd is crappy and PowerShell has not really settled yet. What's more Python can run on several platform so it's a better investment. Finally, Python has a huge set of library so you will almost never hit the "god-I-can't-do-that" wall. This is not true for cmd and PowerShell.
In a Linux environment, this is a bit different. A lot of one liners are shorter, faster, more efficient and often more readable in pure Bash. But if you know your quick and dirty script is going to stay around for a while or will need to be improved, go for Python since it's far easier to maintain and extend and you will be able to do most of the task you can do with GNU tools with the standard library. And if you can't, you can still call the command-line from a Python script.
And of course you can call Python from the shell using -c option:
python -c "for line in open('/etc/fstab') : print line"
Some more literature about Python used for system administration tasks:
The IBM lab point of view.
A nice example to compare bash and python to script report.
The basics.
The must-have book.
Sure, python is a pretty good choice for those tasks (I'm sure many will recommend PowerShell instead).
Here is a fine introduction from that point of view:
http://www.redhatmagazine.com/2008/02/07/python-for-bash-scripters-a-well-kept-secret/
EDIT: About gnud's concern: http://www.portablepython.com/
Are you aware of PowerShell?
Anything is a good replacement for the Batch file system in windows. Perl, Python, Powershell are all good choices.
#BKB definitely has a valid concern. Here's a couple links you'll want to check if you run into any issues that can't be solved with the standard library:
Pywin32 is a package for working with low-level win32 APIs (advanced file system modifications, COM interfaces, etc.)
Tim Golden's Python page: he maintains a WMI wrapper package that builds off of Pywin32, but be sure to also check out his "Win32 How Do I" page for details on how to accomplish typical Windows tasks in Python.
Python is certainly well suited to that. If you're going down that road, you might also want to investigate SCons which is a build system itself built with Python. The cool thing is the build scripts are actually full-blown Python scripts themselves, so you can do anything in the build script that you could otherwise do in Python. It makes make look pretty anemic in comparison.
Upon rereading your question, I should note that SCons is more suited to building software projects than to writing system maintenance scripts. But I wouldn't hesitate to recommend Python to you in any case.
As a follow up, after some experimentation the thing I've found Python most useful for is any situation involving text manipulation (yourStringHere.replace(), regexes for more complex stuff) or testing some basic concept really quickly, which it is excellent for.
For stuff like SQL DB restore scripts I find I still usually just resort to batch files, as it's usually either something short enough that it actually takes more Python code to make the appropriate system calls or I can reuse snippets of code from other people reducing the writing time to just enough to tweak existing code to fit my needs.
As an addendum I would highly recommend IPython as a great interactive shell complete with tab completion and easy docstring access.
I've done a decent amount of scripting in both Linux/Unix and Windows environments, in Python, Perl, batch files, Bash, etc. My advice is that if it's possible, install Cygwin and use Bash (it sounds from your description like installing a scripting language or env isn't a problem?). You'll be more comfortable with that since the transition is minimal.
If that's not an option, then here's my take. Batch files are very kludgy and limited, but make a lot of sense for simple tasks like 'copy some files' or 'restart this service'. Python will be cleaner, easier to maintain, and much more powerful. However, the downside is that either you end up calling external applications from Python with subprocess, popen or similar. Otherwise, you end up writing a bunch more code to do things that are comparatively simple in batch files, like copying a folder full of files. A lot of this depends on what your scripts are doing. Text/string processing is going to be much cleaner in Python, for example.
Lastly, it's probably not an attractive alternative, but you might also consider VBScript as an alternative. I don't enjoy working with it as a language personally, but if portability is any kind of concern then it wins out by virtue of being available out of the box in any copy of Windows. Because of this I've found myself writing scripts that were unwieldy as batch files in VBScript instead, since I can't usually depend on Python or Perl or Bash being available on Windows.
Python, along with Pywin32, would be fine for Windows automation. However, VBScript or JScript used with the Windows Scripting Host works just as well, and requires nothing additional to install.
I've been using a lot of Windows Script Files lately. More powerful than batch scripts, and since it uses Windows scripting, there's nothing to install.
As much as I love python, I don't think it a good choice to replace basic windows batch scripts.
I can't see see someone having to import modules like sys, os or getopt to do basic things you can do with shell like call a program, check environment variable or an argument.
Also, in my experience, goto is much easier to understand to most sysadmins than a function call.
I have started on a personal python application that runs on the desktop. I am using wxPython as a GUI toolkit. Should there be a demand for this type of application, I would possibly like to commercialize it.
I have no knowledge of deploying "real-life" Python applications, though I have used py2exe in the past with varied success. How would I obfuscate the code? Can I somehow deploy only the bytecode?
An ideal solution would not jeopardize my intellectual property (source code), would not require a direct installation of Python (though I'm sure it will need to have some embedded interpreter), and would be cross-platform (Windows, Mac, and Linux). Does anyone know of any tools or resources in this area?
Thanks.
You can distribute the compiled Python bytecode (.pyc files) instead of the source. You can't prevent decompilation in Python (or any other language, really). You could use an obfuscator like pyobfuscate to make it more annoying for competitors to decipher your decompiled source.
As Alex Martelli says in this thread, if you want to keep your code a secret, you shouldn't run it on other people's machines.
IIRC, the last time I used cx_Freeze it created a DLL for Windows that removed the necessity for a native Python installation. This is at least worth checking out.
Wow, there are a lot of questions in there:
It is possible to run the bytecode (.pyc) file directly from the Python interpreter, but I haven't seen any bytecode obfuscation tools available.
I'm not aware of any "all in one" deployment solution, but:
For Windows you could use NSIS(http://nsis.sourceforge.net/Main_Page). The problem here is that while OSX/*nix comes with python, Windows doesn't. If you're not willing to build a binary with py2exe, I'm not sure what the licensing issues would be surrounding distribution of the Python runtime environment (not to mention the technical ones).
You could package up the OS X distribution using the "bundle" format, and *NIX has it's own conventions for installing software-- typically a "make install" script.
Hope that was helpful.
Maybe IronPython can provide something for you? I bet those .exe/.dll-files can be pretty locked down. Not sure how such features work on mono, thus no idea how this works on Linux/OS X...
I have been using py2exe with good success on Windows. The code needs to be modified a bit so that the code analysis picks up all modules needed, but apart from that, it works.
As for Linux, there are several important distribution formats:
DEB (Debian, Ubuntu and other derivatives)
RPM (RedHat, Fedora, openSuSE)
DEBs aren't particularly difficult to make, especially when you're already using distutils/setuptools. Some hints are given in the policy document, examples for packaging Python applications can be found in the repository.
I don't have any experience with RPM, but I'm sure there are enough examples to be found.
Try to use scraZ obfuscator (http://scraZ.me).
This is obfuscator for bytecode, not for source code.
Free version have good, but not perfect obfuscation methods.
PRO version have very very strong protection for bytecode.
(after bytecode obfuscation a decompilation is impossible)