deploy.py

from install import *

packages= [
		Package(name="Vim", posix=[
				SymlinkTask("./.vimrc", "~/.vimrc")
			])
	]

install(packages)

install.py

#!/usr/bin/env python
import os
from os.path import *

DEFAULT_INSTALL = "deploy.py"

class RunnableList(list):
	def run(self):
		for item in self:
			item.run()

class Package(object):
	def __init__(self, name, common=[], posix=[], nt=[]):
		self.name = name
		self.common = RunnableList(common)
		self.posix = RunnableList(posix)
		self.nt = RunnableList(nt)

	def run(self):
		print "Installing package '%s'" % self.name
		self.common.run()
		if os.name is "posix":
			self.posix.run()
		elif os.name is "nt":
			self.nt.run()

class TaskError(Exception):
	pass

class SymlinkTask(object):
	def __init__(self, source, name):
		self.source = normpath(expanduser(source))
		self.name = (expanduser(name))

	@staticmethod
	def symlink_ntfs(source, name):
		import ctypes
		flags = 1 if isdir(source) else 0
		kdll = ctypes.windll.LoadLibrary("kernel32.dll")
		if kdll.CreateSymbolicLinkA(name, source, flags) is 0:
			raise TaskError("Cannot create symbolic link: %s" % ctypes.FormatError())

	@staticmethod
	def symlink(source, name):
		if os.name is "posix":
			os.symlink(source, name)
		elif os.name is "nt":
			SymlinkTask.symlink_ntfs(source, name)
		else:
			raise TaskError("Unsupported system")

	def run(self):
		SymlinkTask.symlink(self.source, self.name)

def module_name(path):
	return splitext(path)[0]

def parse_options():
	from optparse import OptionParser
	parser = OptionParser()
	parser.add_option("-a", "--all", action="store_true", dest="all")
	parser.add_option("-p", "--packages", action="store_true", dest="packages")
	return parser.parse_args()

def install(tasks):
	tasks = RunnableList(tasks)
	options, args = parse_options()
	if options.all:
		tasks.run()
	if options.packages:
		for package in filter(lambda p: p.name in args, tasks):
			package.run()
	if not (options.all or options.packages):
		print "Installable packages:"
		for package in tasks:
			print package.name

if __name__ == "__main__":
	if isfile(DEFAULT_INSTALL):
		__import__(module_name(DEFAULT_INSTALL), globals(), locals())