Source code for foundations.common

#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
**common.py**

**Platform:**
	Windows, Linux, Mac Os X.

**Description:**
	Defines **Foundations** package common utilities objects that don't fall in any specific category.

**Others:**
	:func:`isBinaryFile` from Jorge Orpinel:
	http://stackoverflow.com/questions/898669/how-can-i-detect-if-a-file-is-binary-non-text-in-python
	:func:`dependencyResolver` from Louis Riviere: http://code.activestate.com/recipes/576570-dependency-resolver/

"""

#**********************************************************************************************************************
#***	Future imports.
#**********************************************************************************************************************
from __future__ import unicode_literals

#**********************************************************************************************************************
#***	External imports.
#**********************************************************************************************************************
import itertools
import os
import socket
import urllib2

#**********************************************************************************************************************
#***	Internal imports.
#**********************************************************************************************************************
import foundations.verbose
from foundations.globals.constants import Constants

#**********************************************************************************************************************
#***	Module attributes.
#**********************************************************************************************************************
__author__ = "Thomas Mansencal"
__copyright__ = "Copyright (C) 2008 - 2014 - Thomas Mansencal"
__license__ = "GPL V3.0 - http://www.gnu.org/licenses/"
__maintainer__ = "Thomas Mansencal"
__email__ = "thomas.mansencal@gmail.com"
__status__ = "Production"

__all__ = ["LOGGER",
		"CONNECTION_IPS",
		"DEFAULT_HOST_IP",
		"wait",
		"uniqify",
		"unpackDefault",
		"orderedUniqify",
		"pathExists",
		"filterPath",
		"getFirstItem",
		"getLastItem",
		"repeat",
		"dependencyResolver",
		"isInternetAvailable",
		"getHostAddress"]

LOGGER = foundations.verbose.installLogger()

CONNECTION_IPS = ["173.194.34.36",  # http://www.google.com
				"173.194.34.55",  # http://www.google.co.uk
				"65.55.206.154",  # http://www.live.com
				"173.252.110.27",  # http://www.facebook.com
				"199.16.156.230",  # http://www.twitter.com
				"98.139.183.24",  # http://www.yahoo.com
				"77.238.178.122",  # http://www.yahoo.co.uk
				"198.252.206.16",  # http://www.stackoverflow.com
				"82.94.164.162",  # http://www.python.org
				"65.196.127.226",  # http://www.nsa.gov :D
				"www.google.com",
				"www.facebook.com",
				"www.twitter.com"]
DEFAULT_HOST_IP = "127.0.0.1"

#**********************************************************************************************************************
#***	Module classes and definitions.
#**********************************************************************************************************************
[docs]def uniqify(sequence): """ Uniqifies the given sequence even if unhashable. :param sequence: Sequence. :type sequence: object :return: Uniqified sequence. :rtype: list :note: The sequence order is not maintained by this definition. """ return [key for key, group in itertools.groupby(sorted(sequence))]
[docs]def orderedUniqify(sequence): """ Uniqifies the given hashable sequence while preserving its order. :param sequence: Sequence. :type sequence: object :return: Uniqified sequence. :rtype: list """ items = set() return [key for key in sequence if key not in items and not items.add(key)]
[docs]def unpackDefault(iterable, length=3, default=None): """ Unpacks given iterable maintaining given length and filling missing entries with given default. :param iterable: iterable. :type iterable: object :param length: Iterable length. :type length: int :param default: Filling default object. :type default: object :return: Unpacked iterable. :rtype: object """ return itertools.islice(itertools.chain(iter(iterable), itertools.repeat(default)), length)
[docs]def pathExists(path): """ Returns if given path exists. :param path: Path. :type path: unicode :return: Path existence. :rtype: bool """ if not path: return False else: return os.path.exists(path)
[docs]def filterPath(path): """ Filters given path. :param path: Path. :type path: unicode :return: Filtered path. :rtype: unicode """ return path if pathExists(path) else ""
[docs]def getFirstItem(iterable, default=None): """ Returns the first item of given iterable. :param iterable: Iterable. :type iterable: object :param default: Default value. :type default: object :return: First iterable item. :rtype: object """ if not iterable: return default for item in iterable: return item
[docs]def getLastItem(iterable, default=None): """ Returns the last item of given iterable. :param iterable: Iterable. :type iterable: object :param default: Default value. :type default: object :return: Last iterable item. :rtype: object """ if not iterable: return default return iterable[-1]
[docs]def repeat(object, iterations=1): """ Repeats given object iterations times. :param object: Object to repeat. :type object: object :param iterations: Repetitions number. :type iterations: int :return: Object return values. :rtype: list """ return [object() for i in range(iterations)]
[docs]def dependencyResolver(dependencies): """ Resolves given dependencies. :param dependencies: Dependencies to resolve. :type dependencies: dict :return: Resolved dependencies. :rtype: list """ items = dict((key, set(dependencies[key])) for key in dependencies) resolvedDependencies = [] while items: batch = set(item for value in items.values() for item in value) - set(items.keys()) batch.update(key for key, value in items.items() if not value) resolvedDependencies.append(batch) items = dict(((key, value - batch) for key, value in items.items() if value)) return resolvedDependencies
[docs]def isInternetAvailable(ips=CONNECTION_IPS, timeout=1.0): """ Returns if an internet connection is available. :param ips: Address ips to check against. :type ips: list :param timeout: Timeout in seconds. :type timeout: int :return: Is internet available. :rtype: bool """ while ips: try: urllib2.urlopen("http://{0}".format(ips.pop(0)), timeout=timeout) return True except IndexError as error: continue except (urllib2.URLError, socket.error) as error: continue return False
[docs]def getHostAddress(host=None, defaultAddress=DEFAULT_HOST_IP): """ Returns the given host address. :param host: Host to retrieve the address. :type host: unicode :param defaultAddress: Default address if the host is unreachable. :type defaultAddress: unicode :return: Host address. :rtype: unicode """ try: return unicode(socket.gethostbyname(host or socket.gethostname()), Constants.defaultCodec, Constants.codecError) except Exception as error: return defaultAddress