IronPython: EXE compiled using pyc.py cannot import module "os"

Question

I have a simple IronPython script:

# Foo.py
import os

def main():
    print( "Hello" )

if "__main__" == __name__:
    main()

It runs fine and prints Hello if I run it with IronPython as:

ipy Foo.py

Following the instructions given in IronPython - how to compile exe, I compiled this IronPython script to a EXE using:

ipy pyc.py /main:Foo.py /target:exe

Executing Foo.exe gives this error:

Unhandled Exception: IronPython.Runtime.Exceptions.ImportException: No module named os
   at Microsoft.Scripting.Runtime.LightExceptions.CheckAndThrow(Object value)
   at DLRCachedCode.__main__$1(CodeContext $globalContext, FunctionCode $functionCode)
   at IronPython.Compiler.OnDiskScriptCode.Run()
   at IronPython.Compiler.OnDiskScriptCode.Run(Scope scope)
   at IronPython.Runtime.PythonContext.InitializeModule(String fileName, ModuleContext moduleContext, ScriptCode scriptC
ode, ModuleOptions options)

Why cannot module "os" be found? How do I fix this, so I can get a working EXE?

(Note that this is different from the question IronPython cannot import module os since the script works fine if I run with ipy.exe.)

Answer 1

Building an Ironpython EXE that you can distribute is a bit tricky - especially if you are using elements of the standard library. My typical solution is the following:

I copy all of the stdlib modules I need into a folder (usually all of them just for completeness) and use this script to build my exe. In this example I have two files FredMain.py and FredSOAP.py that get compiled into an EXE called Fred_Download_Tool

import sys
sys.path.append(r'C:\Program Files\IronPython 2.7\Lib')
sys.path.append(r'C:\Program Files\IronPython 2.7')
import clr

clr.AddReference('IronPython')
clr.AddReference('IronPython.Modules')
clr.AddReference('Microsoft.Scripting.Metadata')
clr.AddReference('Microsoft.Scripting')
clr.AddReference('Microsoft.Dynamic')
clr.AddReference('mscorlib')
clr.AddReference('System')
clr.AddReference('System.Data')

#
# adapted from os-path-walk-example-3.py

import os, glob
import fnmatch
import pyc

def doscopy(filename1):
    print filename1
    os.system ("copy %s .\\bin\Debug\%s" % (filename1, filename1))

class GlobDirectoryWalker:
    # a forward iterator that traverses a directory tree

    def __init__(self, directory, pattern="*"):
        self.stack = [directory]
        self.pattern = pattern
        self.files = []
        self.index = 0

    def __getitem__(self, index):
        while 1:
            try:
                file = self.files[self.index]
                self.index = self.index + 1
            except IndexError:
                # pop next directory from stack
                self.directory = self.stack.pop()
                self.files = os.listdir(self.directory)
                self.index = 0
            else:
                # got a filename
                fullname = os.path.join(self.directory, file)
                if os.path.isdir(fullname) and not os.path.islink(fullname) and fullname[-4:]<>'.svn':
                    self.stack.append(fullname)
                if fnmatch.fnmatch(file, self.pattern):
                    return fullname

#Build StdLib.DLL
gb = glob.glob(r".\Lib\*.py")
gb.append("/out:StdLib")    

#print ["/target:dll",]+gb

pyc.Main(["/target:dll"]+gb)

#Build EXE
gb=["/main:FredMain.py","FredSOAP.py","/target:exe","/out:Fred_Download_Tool"]
pyc.Main(gb)


#CopyFiles to Release Directory
doscopy("StdLib.dll")
doscopy("Fred_Download_Tool.exe")
doscopy("Fred_Download_.dll")


#Copy DLLs to Release Directory
fl = ["IronPython.dll","IronPython.Modules.dll","Microsoft.Dynamic.dll","Microsoft.Scripting.Debugging.dll","Microsoft.Scripting.dll","Microsoft.Scripting.ExtensionAttribute.dll","Microsoft.Scripting.Core.dll"]
for f in fl:

doscopy(f)

In my scripts I add the following when I am ready to compile. This allows the program to use the Standard Modules from my DLL instead of the Python Install. This is necessary if you want to distribute to people without Python installed. Just make sure you include the necessary DLL's when you create your installer.

#References to created DLL of python modules
clr.AddReference('StdLib')