Python standard library

[arisawa]

When I coding the cobra and want to use a Python standard library, is there the way?

[Charles]

Not currently. Someday Cobra will support Microsoft's Dynamic Language Runtime (DLR), using it for dynamic dispatch. Then you should be able to use pure Python libraries through IronPython. But we don't have that right now.

[Charles]

By the way, was there a particular library or libraries that you wanted to use from Python? Just curious.

[arisawa]

Hi, Chuck.
It is a glob module that I wanted to use.

[arisawa]

sorry, off topic

Does not Cobra follow it by built-in function of Python?
Does Cobra have pound-bang line? the example?

because I learn Cobra, Python and C# in side by side, I meet with such a confusion and questions well.

[Charles]

sorry, off topic

These questions are fine.

Does not Cobra follow it by built-in function of Python?

Cobra uses the .NET/Mono libraries. So if you want to find the built-in functions for something you can search Google for "C# read directories" or whatever you like. Eventually, we'll have a cross platform library that runs on both .NET and JVM, but that won't be for awhile.

Does Cobra have pound-bang line? the example?

It's supposed to, but I just tried "#!/usr/bin/cobra" on my Mac and it failed for reasons that I researched before. Basically, unix is not very flexible in allowing the pound-bang command to be another script which is what "/usr/bin/cobra" is. I was able to do this though:

#!/bin/bash cobra

class X

    def main
        print 'Hello.'

Or if you prefer, you can make the path to cobra absolute:

#!/bin/bash /usr/bin/cobra
...

because I learn Cobra, Python and C# in side by side, I meet with such a confusion and questions well.

No problem.

[eric.sellon]

Just for fun, here's a sample Cobra program calling into IronPython

Code: Select all

use IronPython.Hosting
use IronPython.Runtime.Types
use IronPython.Runtime.Operations

class Program

    def main is shared
        """ Test docstring """
        engine = PythonEngine()
        code = 'print "This is IronPython"'
        engine.execute(code)


I called this program CallingIronPython.cobra. I used IronPython 1.1.0 (the API changed with IronPython 2.0) and had IronPython.dll and IronMath.dll in the same directory as the cobra file. Ran Cobra with the command line: cobra -r:IronPython.dll CallingIronPython
A good resource (especially if you want to work with IronPython 2.0) is http://www.voidspace.org.uk/ironpython/embedding.shtml
Hope that helps.

[Charles]

That's great. Would make a nice wiki page. hint, hint.

[eric.sellon]

Would make a nice wiki page. hint, hint.

Done. Made a Cobra Cookbook on the wiki and added this recipe -> http://cobra-language.com/trac/cobra/wiki/CallingIronPythonRecipe

[arisawa]

Wow! It is a helpful idea.
I wrote a sample to try:

use System.Windows.Forms
use IronPython.Hosting

class Calc inherits Form
    var tb as TextBox
    var pe as PythonEngine = PythonEngine()
    var s as Str = Str()
    
    cue init
       base.init
    .text = 'SimpleCalc'
    flp = FlowLayoutPanel(parent=this, dock=DockStyle.Fill, flowDirection=FlowDirection.TopDown)
    .tb = TextBox(parent=flp)
    b = Button(text='done', parent=flp)
    listen b.click, ref .handleClick
    .pe.globals.add('TextBox', .tb)
    .pe.globals.add('Str', .s)
        
    def handleClick(sender, args as EventArgs)
    .pe.execute('TextBox.Text =' + 'Str.Pack('+.tb.text+')')
        
class Str
    def pack(n as int) as String
    return n.toString
        
class Program
    def main is shared
    Application.run(Calc())

In the tried feeling
Python code seems to run if it does in this way:

engine = PythonEngine()
file = 'test.py'
engine.executeFile(file)

but, still rocky.