In the nautilus-python bindings, there is a file "nautilus.defs". It contains stanzas like
(define-interface MenuProvider
(in-module "Nautilus")
(c-name "NautilusMenuProvider")
(gtype-id "NAUTILUS_TYPE_MENU_PROVIDER")
)
or
(define-method get_mime_type
(of-object "NautilusFileInfo")
(c-name "nautilus_file_info_get_mime_type")
(return-type "char*")
)
Now I can see what most of these do (eg. that last one means that I can call the method "get_mime_type" on a "FileInfo" object). But I'd like to know: what is this file, exactly (ie. what do I search the web for to find out more info)? Is it a common thing to find in Python/C bindings? What is the format, and where is it documented? What program actually processes it?
(So far, I've managed to glean that it gets transformed into a C source file, and it looks a bit like lisp to me.)
To answer your "What program actually processes it?" question:
From Makefile.in in the src directory, the command that translates the .defs file into C is PYGTK_CODEGEN. To find out what PYGTK_CODEGEN is, look in the top-level configure.in file, which contains these lines:
AC_MSG_CHECKING(for pygtk codegen)
PYGTK_CODEGEN="$PYTHON `$PKG_CONFIG --variable=codegendir pygtk-2.0`/codegen.py"
AC_SUBST(PYGTK_CODEGEN)
AC_MSG_RESULT($PYGTK_CODEGEN)
So the program that processes it is a Python script called codegen.py, that apparently has some link with PyGTK. Now a Google search for PyGTK codegen gives me this link as the first hit, which says:
"PyGTK-Codegen is a system for automatically generating wrappers for interfacing GTK code with Python."
and also gives some examples.
As for: "What is the format, and where is it documented?". As others have said, the code looks a lot like simple Scheme. I couldn't find any documentation at all on codegen on the PyGTK site; this looks like one of those many dark corners of open source that isn't well documented. Your best bet would probably be to download a recent tarball for PyGTK, look through the sources for the codegen.py file and see if the file itself contains sufficient documentation.
All you need to create Python bindings for C code is to use the Python / C API. However, the API can be somewhat repetitive and redundant, and so various forms of automation may be used to create them. For example, you may have heard of swig. The LISP-like (Scheme) code that you see is simply a configuration file for PyGTK-Codegen, which is a similar automation program for creating bindings to Python.
Related
So, I recently made a Python program that I want to send to someone with them being able to execute it, but not read the code I have typed in it. Any ideas how to do it?
BTW, I want it to be irreversible
In short, here are my Parameters:
Should remain a Python file
Can't be reversed
Code should not be readable
Should still have the ability to be run
The criteria you've posted are inconsistent.
Python is an interpreted language. The entity running the language (i.e. Python interpreter) is reading your code and executing it, line by line. If you wrap it up to send to someone, their Python interpreter must have read permissions on the file, whether it's source code or "compiled" Python (which is easily decompiled into equivalent source code).
If we take a wider interpretation of "send to someone", there may be a business solution that serves your needs. You would provide your functionality, rather than the code: deploy it as a service from some available server: your own, or rented space. To do this, you instead provide an interface to your functionality.
If this fulfills your needs, you now have your next research topic.
I have written a Python script which models an academic problem which I wish to publish. I will put the source on Github and some academics that just happen to know Python may get my source and play with it themselves. However there are probably more academics that may be interested in the model but that are not python programmers and I would like them to be able to run my model too. Even though they are not programmers they could at least try out editing the values of some of the parameters to see how that affects the results. So now my question is how could I arrange for a non-python programmer to run a Python program as easily (for them) as possible. I would guess that my options may be...
google colab
an online python compiler like this one
compiling the program into an exe (and letting the user set parameters via a config file)
something else?
So now a couple of complications that makes my problem trickier.
The output of the program is graphical and uses matplotlib. As I understand it, the utilities that turn python scripts into exe files struggle or fail altogether when it comes to matplotlib.
The source is split into two separate files, one small neat file which contains the model and the user might like to have a good look at it and get the gist of it even if they're not really a python programmer. And a separate large ugly file which just handles the graphics - an academic would have no interest in this and I'd like to spare them the gory details.
EDIT: I did ask a related question here - but that was all about programmers that won't mind doing things like installing python and using pip... this question is in relation to non-programmers who would not be comfortable doing things like that.
Colab can handle the 2 problems, but you may need to adapt some code.
Matplotlib interface: Colab can display plots just fine. But you may want user to interact with slider, checkbox, dropdown menu. Then, you need to use Colab's own Form UI, or pywidgets. See an example here
2 separate python files: you can convert one of them to a notebook. Then import the other. Or you can create a new notebook that import both files. Here's an example.
Has someone implemented the CSV-handling for Flyway? It was requested some time ago (Flyway specific migration with csv files). Flyway comments it now as a possibility for the MigrationResolver and MigrationExecutor, but it does not seem to be implemented.
I've tried to do it myself with Flyway 4.2, but I'm not very good with java. I got as far as creating my own jar using the sample and make it accessible to flyway. But how does flyway distinguish when to use the SqlMigrator and when to use my CsvMigrator? I thought I have to register my own prefix/suffix (as the question above writes), but FlywayConfiguration seems to be read-only, at least I did not see any API calls for doing this :(.
How to connect the different Resolvers to the different migration file types? (.sql to the migration using Sql and .csv/.py to the loading of Csv and executing python scripts)
After some shed of tears and blood, it looks like came up with something on this. I can't make the whole code available because it is using proprietary file format, but here's the main ideas:
implement the ConfigurationAware as well, and use the setFlywayConfiguration implementation to catalog the extra files you want to handle (i.e. .csv). This is executed only once during the run.
during this cataloging I could not use the scanner or LoadableResources, there's some Java magic I do not understand. All the classes and methods seem to be available and accessible, even when using .getMethods() runtime... but when trying to actually call them during a run it throws java.lang.NoSuchMethodError and java.lang.NoClassDefFoundError. I've wasted a whole day on this - don't do that, just copy-paste the code from org.flywaydb.core.internal.util.scanner.filesystem.FileSystemScanner.
use Set< String > instead of LoadableResources[], way easier to work with, especially since there's no access to LoadableResources anyway and working with [] was a nightmare.
the python/shell call will go to the execute(). Some tips:
any exception or fawlty exitcode needs to be translated to an SQLException.
the build is enforcing Java 1.6, so new ProcessBuilder(cmd).inheritIO() cannot be used. Look at these solutions: ProcessBuilder: Forwarding stdout and stderr of started processes without blocking the main thread if you want to print the STDOUT/STDERR.
to compile flyway including your custom module, clone the whole flyway repo from git, edit the main pom.xml to include your module as well and use this command to compile: "mvn install -P-CommercialDBTest -P-CommandlinePlatformAssemblies -DskipTests=true" (I found this in another stackoverflow question.)
what I haven't done yet is the checksum part, I don't know yet what that wants.
What I really want to do is determine whether a particular file in the MSI exists and contains a particular string.
My current idea is to run:
db = msilib.OpenDatabase('c:\Temp\myfile.msi',1)
query = "select * from File"
view = db.OpenView(query)
view.Execute(None)
cur_record = view.Fetch() # do this until I get the record I want
print cur_record.GetString(3) # do stuff with this value
And then if it's there, extract all the files using
msiexec /a c:\Temp\myfile.msi /qn TARGETDIR=c:\foo
and use whatever parser to see whether my string is there. But I'm hoping a less clunky way exists.
Note that, as the docs for msilib say, "Support for reading .cab files is currently not implemented". And. more generally, the library is designed for building .msi files, not reading them. And there is nothing else in the stdlib that will do what you want.
So, there are a few possibilities:
Find and install another library, like pycabinet. I know nothing about this particular library; it's just the first search hit I got; you probably want to search on your own. But it claims to provide a zipfile-like API for CAB files, which sounds like exactly the part you're missing.
Use win32com (if you've got pywin32) or ctypes (if you're a masochist) to talk to the underlying COM interfaces and/or the classic Cabinet API (which I think is now deprecated, but still works).
Use IronPython instead of CPython, so you can use the simpler .NET interfaces.
Since I don't have a Windows box here, I can't test this, but here's a sketch of Christopher Painter's .NET solution written in IronPython instead of C#:
import clr
clr.AddReference('Microsoft.Deployment.WindowsInstaller')
clr.AddReference('Microsoft.Deployment.WindowsInstaller.Package')
from Microsoft.Deployment.WindowsInstaller import *
from Microsoft.Deployment.WindowsInstaller.Package import *
def FindAndExtractFiles(packagePath, longFileName):
with InstallPackage(packagePath, DatabaseOpenMode.ReadOnly) as installPackage:
if installPackage.FindFiles(longFileName).Count() > 0:
installPackage.ExtractFiles()
Realize that in using Python you have to deal with the Windows Installer (COM) Automation interface. This means you have to do all the database connections, querying and processing yourself.
If you could move to C# ( or say PowerShell ) you could leverage some higher level classes that exist in Windows Installer XML (WiX) Deployment Tools Foundation (DTF).
using Microsoft.Deployment.WindowsInstaller;
using Microsoft.Deployment.WindowsInstaller.Package;
static void FindAndExtractFiles(string packagePath, string longFileName)
{
using (var installPackage = new InstallPackage(packagePath, DatabaseOpenMode.ReadOnly))
{
if(installPackage.FindFiles(longFileName).Count() > 0 )
installPackage.ExtractFiles();
}
}
You could also write this as ComVisible(True) and call it from Python.
The MSI APIs are inherently clunky, so it's only a matter of where the abstraction lies. Bear in mind that if you just need this a couple times, it may be easier to browse the cab file(s) manually in Explorer. (Files are stored by file key instead of file name).
Most rails modes for emacs have this kind of functionality. You are in a controller file over a function "kaboosh" in
"app/controller/bla.rb" and with a keyboard shortcut you switch to "app/views/kaboosh.erb" or to app/models/bla.rb".
A similar functionality exists for .c and .h files using ff-find-other-file.
I checked jump.el and findr.el but all seems a little bit complicated.
I tried searching this for django projects (it would have helped a lot) but no luck.
Anyone knows a simple way (etags?) that it's easy to define the connection between current file/function and target file and then bind it to a keyboard shortcut?
Tags is set up well to jump you to the definition of a function. M-. will take you to the first occurrence of a function definition, C-u M-. will take you to the next (and one after that, and after that...). Perhaps the C-u M-. solves some of your problem.
Regarding associations between files, and wanting a rails like interface, it looks like you could pull out the appropriate chunks of code and customize them for python.
Specifically, you'll need the jump package, make a similar jump schema like the rinari-jump-schema (found in rinari.el). The jump schema uses 'ruby-add-log-current-method (found in ruby-mode.el), and you'd just need to customize that to return the current method name for Python syntax.
It doesn't look like anyone has done this for Python yet, you could be the first. I believe those are the only pieces you'll need.