Application: gvSIG desktop » gvSIG scripting

"""Utilities for writing code that runs on Python 2 and 3"""

#Copyright (c) 2010-2011 Benjamin Peterson

#Permission is hereby granted, free of charge, to any person obtaining a copy of

#this software and associated documentation files (the "Software"), to deal in

#the Software without restriction, including without limitation the rights to

#use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of

#the Software, and to permit persons to whom the Software is furnished to do so,

#subject to the following conditions:

#The above copyright notice and this permission notice shall be included in all

#copies or substantial portions of the Software.

#THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

#IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS

#FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR

#COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER

#IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

#CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

import operator

import sys

import types

__author__ = "Benjamin Peterson <benjamin@python.org>"

__version__ = "1.2.0"  # Revision 41c74fef2ded

# True if we are running on Python 3.

PY3 = sys.version_info[0] == 3

if PY3:

    string_types = str,

    integer_types = int,

    class_types = type,

    text_type = str

    binary_type = bytes

    MAXSIZE = sys.maxsize

else:

    string_types = basestring,

    integer_types = (int, long)

    class_types = (type, types.ClassType)

    text_type = unicode

    binary_type = str

    if sys.platform.startswith("java"):

        # Jython always uses 32 bits.

        MAXSIZE = int((1 << 31) - 1)

    else:

        # It's possible to have sizeof(long) != sizeof(Py_ssize_t).

        class X(object):

            def __len__(self):

                return 1 << 31

        try:

            len(X())

        except OverflowError:

            # 32-bit

            MAXSIZE = int((1 << 31) - 1)

        else:

            # 64-bit

            MAXSIZE = int((1 << 63) - 1)

            del X

def _add_doc(func, doc):

    """Add documentation to a function."""

    func.__doc__ = doc

def _import_module(name):

    """Import module, returning the module after the last dot."""

    __import__(name)

    return sys.modules[name]

class _LazyDescr(object):

    def __init__(self, name):

        self.name = name

    def __get__(self, obj, tp):

        result = self._resolve()

        setattr(obj, self.name, result)

        # This is a bit ugly, but it avoids running this again.

        delattr(tp, self.name)

        return result

class MovedModule(_LazyDescr):

    def __init__(self, name, old, new=None):

        super(MovedModule, self).__init__(name)

        if PY3:

            if new is None:

                new = name

            self.mod = new

        else:

            self.mod = old

    def _resolve(self):

        return _import_module(self.mod)

class MovedAttribute(_LazyDescr):

    def __init__(self, name, old_mod, new_mod, old_attr=None, new_attr=None):

        super(MovedAttribute, self).__init__(name)

        if PY3:

            if new_mod is None:

                new_mod = name

            self.mod = new_mod

            if new_attr is None:

                if old_attr is None:

                    new_attr = name

                else:

                    new_attr = old_attr

            self.attr = new_attr

        else:

            self.mod = old_mod

            if old_attr is None:

                old_attr = name

            self.attr = old_attr

    def _resolve(self):

        module = _import_module(self.mod)

        return getattr(module, self.attr)

class _MovedItems(types.ModuleType):

    """Lazy loading of moved objects"""

_moved_attributes = [

    MovedAttribute("cStringIO", "cStringIO", "io", "StringIO"),

    MovedAttribute("filter", "itertools", "builtins", "ifilter", "filter"),

    MovedAttribute("input", "__builtin__", "builtins", "raw_input", "input"),

    MovedAttribute("map", "itertools", "builtins", "imap", "map"),

    MovedAttribute("reload_module", "__builtin__", "imp", "reload"),

    MovedAttribute("reduce", "__builtin__", "functools"),

    MovedAttribute("StringIO", "StringIO", "io"),

    MovedAttribute("xrange", "__builtin__", "builtins", "xrange", "range"),

    MovedAttribute("zip", "itertools", "builtins", "izip", "zip"),

    MovedModule("builtins", "__builtin__"),

    MovedModule("configparser", "ConfigParser"),

    MovedModule("copyreg", "copy_reg"),

    MovedModule("http_cookiejar", "cookielib", "http.cookiejar"),

    MovedModule("http_cookies", "Cookie", "http.cookies"),

    MovedModule("html_entities", "htmlentitydefs", "html.entities"),

    MovedModule("html_parser", "HTMLParser", "html.parser"),

    MovedModule("http_client", "httplib", "http.client"),

    MovedModule("BaseHTTPServer", "BaseHTTPServer", "http.server"),

    MovedModule("CGIHTTPServer", "CGIHTTPServer", "http.server"),

    MovedModule("SimpleHTTPServer", "SimpleHTTPServer", "http.server"),

    MovedModule("cPickle", "cPickle", "pickle"),

    MovedModule("queue", "Queue"),

    MovedModule("reprlib", "repr"),

    MovedModule("socketserver", "SocketServer"),

    MovedModule("tkinter", "Tkinter"),

    MovedModule("tkinter_dialog", "Dialog", "tkinter.dialog"),

    MovedModule("tkinter_filedialog", "FileDialog", "tkinter.filedialog"),

    MovedModule("tkinter_scrolledtext", "ScrolledText", "tkinter.scrolledtext"),

    MovedModule("tkinter_simpledialog", "SimpleDialog", "tkinter.simpledialog"),

    MovedModule("tkinter_tix", "Tix", "tkinter.tix"),

    MovedModule("tkinter_constants", "Tkconstants", "tkinter.constants"),

    MovedModule("tkinter_dnd", "Tkdnd", "tkinter.dnd"),

    MovedModule("tkinter_colorchooser", "tkColorChooser",

                "tkinter.colorchooser"),

    MovedModule("tkinter_commondialog", "tkCommonDialog",

                "tkinter.commondialog"),

    MovedModule("tkinter_tkfiledialog", "tkFileDialog", "tkinter.filedialog"),

    MovedModule("tkinter_font", "tkFont", "tkinter.font"),

    MovedModule("tkinter_messagebox", "tkMessageBox", "tkinter.messagebox"),

    MovedModule("tkinter_tksimpledialog", "tkSimpleDialog",

                "tkinter.simpledialog"),

    MovedModule("urllib_robotparser", "robotparser", "urllib.robotparser"),

    MovedModule("winreg", "_winreg"),

]

for attr in _moved_attributes:

    setattr(_MovedItems, attr.name, attr)

del attr

moves = sys.modules[__name__ + ".moves"] = _MovedItems("moves")

def add_move(move):

    """Add an item to six.moves."""

    setattr(_MovedItems, move.name, move)

def remove_move(name):

    """Remove item from six.moves."""

    try:

        delattr(_MovedItems, name)

    except AttributeError:

        try:

            del moves.__dict__[name]

        except KeyError:

            raise AttributeError("no such move, %r" % (name,))

if PY3:

    _meth_func = "__func__"

    _meth_self = "__self__"

    _func_code = "__code__"

    _func_defaults = "__defaults__"

    _iterkeys = "keys"

    _itervalues = "values"

    _iteritems = "items"

else:

    _meth_func = "im_func"

    _meth_self = "im_self"

    _func_code = "func_code"

    _func_defaults = "func_defaults"

    _iterkeys = "iterkeys"

    _itervalues = "itervalues"

    _iteritems = "iteritems"

try:

    advance_iterator = next

except NameError:

    def advance_iterator(it):

        return it.next()

next = advance_iterator

if PY3:

    def get_unbound_function(unbound):

        return unbound

    Iterator = object

    def callable(obj):

        return any("__call__" in klass.__dict__ for klass in type(obj).__mro__)

else:

    def get_unbound_function(unbound):

        return unbound.im_func

    class Iterator(object):

        def next(self):

            return type(self).__next__(self)

    callable = callable

_add_doc(get_unbound_function,

         """Get the function out of a possibly unbound function""")

get_method_function = operator.attrgetter(_meth_func)

get_method_self = operator.attrgetter(_meth_self)

get_function_code = operator.attrgetter(_func_code)

get_function_defaults = operator.attrgetter(_func_defaults)

def iterkeys(d):

    """Return an iterator over the keys of a dictionary."""

    return iter(getattr(d, _iterkeys)())

def itervalues(d):

    """Return an iterator over the values of a dictionary."""

    return iter(getattr(d, _itervalues)())

def iteritems(d):

    """Return an iterator over the (key, value) pairs of a dictionary."""

    return iter(getattr(d, _iteritems)())

if PY3:

    def b(s):

        return s.encode("latin-1")

    def u(s):

        return s

    if sys.version_info[1] <= 1:

        def int2byte(i):

            return bytes((i,))

    else:

        # This is about 2x faster than the implementation above on 3.2+

        int2byte = operator.methodcaller("to_bytes", 1, "big")

    import io

    StringIO = io.StringIO

    BytesIO = io.BytesIO

else:

    def b(s):

        return s

    def u(s):

        return unicode(s, "unicode_escape")

    int2byte = chr

    import StringIO

    StringIO = BytesIO = StringIO.StringIO

_add_doc(b, """Byte literal""")

_add_doc(u, """Text literal""")

if PY3:

    import builtins

    exec_ = getattr(builtins, "exec")

    def reraise(tp, value, tb=None):

        if value.__traceback__ is not tb:

            raise value.with_traceback(tb)

        raise value

    print_ = getattr(builtins, "print")

    del builtins

else:

    def exec_(code, globs=None, locs=None):

        """Execute code in a namespace."""

        if globs is None:

            frame = sys._getframe(1)

            globs = frame.f_globals

            if locs is None:

                locs = frame.f_locals

            del frame

        elif locs is None:

            locs = globs

        exec("""exec code in globs, locs""")

    exec_("""def reraise(tp, value, tb=None):

    raise tp, value, tb

""")

    def print_(*args, **kwargs):

        """The new-style print function."""

        fp = kwargs.pop("file", sys.stdout)

        if fp is None:

            return

        def write(data):

            if not isinstance(data, basestring):

                data = str(data)

            fp.write(data)

        want_unicode = False

        sep = kwargs.pop("sep", None)

        if sep is not None:

            if isinstance(sep, unicode):

                want_unicode = True

            elif not isinstance(sep, str):

                raise TypeError("sep must be None or a string")

        end = kwargs.pop("end", None)

        if end is not None:

            if isinstance(end, unicode):

                want_unicode = True

            elif not isinstance(end, str):

                raise TypeError("end must be None or a string")

        if kwargs:

            raise TypeError("invalid keyword arguments to print()")

        if not want_unicode:

            for arg in args:

                if isinstance(arg, unicode):

                    want_unicode = True

                    break

        if want_unicode:

            newline = unicode("\n")

            space = unicode(" ")

        else:

            newline = "\n"

            space = " "

        if sep is None:

            sep = space

        if end is None:

            end = newline

        for i, arg in enumerate(args):

            if i:

                write(sep)

            write(arg)

        write(end)

_add_doc(reraise, """Reraise an exception.""")

def with_metaclass(meta, base=object):

    """Create a base class with a metaclass."""

    return meta("NewBase", (base,), {})