/usr/lib/python3/dist-packages/pyfits/util.py is in python3-pyfits 1:3.3-2+b1.
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import functools
import gzip
import itertools
import mmap
import os
import signal
import sys
import tempfile
import textwrap
import threading
import warnings
try:
import io
except ImportError:
io = None
try:
from StringIO import StringIO
except ImportError:
class StringIO(object):
pass
import numpy as np
from .extern.six import (PY3, iteritems, string_types, integer_types,
text_type, binary_type, next)
from .extern.six.moves import zip, reduce
BLOCK_SIZE = 2880 # the FITS block size
if PY3:
cmp = lambda a, b: (a > b) - (a < b)
else:
cmp = cmp
def first(iterable):
"""
Returns the first item returned by iterating over an iterable object.
Example:
>>> a = [1, 2, 3]
>>> first(a)
1
"""
return next(iter(iterable))
def itersubclasses(cls, _seen=None):
"""
itersubclasses(cls)
Generator over all subclasses of a given class, in depth first order.
>>> list(itersubclasses(int)) == [bool]
True
>>> class A(object): pass
>>> class B(A): pass
>>> class C(A): pass
>>> class D(B,C): pass
>>> class E(D): pass
>>>
>>> for cls in itersubclasses(A):
... print(cls.__name__)
B
D
E
C
>>> # get ALL (new-style) classes currently defined
>>> [cls.__name__ for cls in itersubclasses(object)] #doctest: +ELLIPSIS
[...'tuple', ...'type', ...]
From http://code.activestate.com/recipes/576949/
"""
if not isinstance(cls, type):
raise TypeError('itersubclasses must be called with '
'new-style classes, not %.100r' % cls)
if _seen is None:
_seen = set()
try:
subs = cls.__subclasses__()
except TypeError: # fails only when cls is type
subs = cls.__subclasses__(cls)
for sub in sorted(subs, key=lambda s: s.__name__):
if sub not in _seen:
_seen.add(sub)
yield sub
for sub in itersubclasses(sub, _seen):
yield sub
class lazyproperty(object):
"""
Works similarly to property(), but computes the value only once.
Adapted from the recipe at
http://code.activestate.com/recipes/363602-lazy-property-evaluation
"""
def __init__(self, fget, fset=None, fdel=None, doc=None):
self._fget = fget
self._fset = fset
self._fdel = fdel
if doc is None:
self.__doc__ = fget.__doc__
else:
self.__doc__ = doc
self._key = self._fget.__name__
def __get__(self, obj, owner=None):
if obj is None:
return self
try:
return obj.__dict__[self._key]
except KeyError:
val = self._fget(obj)
obj.__dict__[self._key] = val
return val
def __set__(self, obj, val):
obj_dict = obj.__dict__
if self._fset:
ret = self._fset(obj, val)
if ret is not None and obj_dict.get(self._key) is ret:
# By returning the value set the setter signals that it took
# over setting the value in obj.__dict__; this mechanism allows
# it to override the input value
return
obj_dict[self._key] = val
def __delete__(self, obj):
if self._fdel:
self._fdel(obj)
if self._key in obj.__dict__:
del obj.__dict__[self._key]
def getter(self, fget):
return self.__ter(fget, 0)
def setter(self, fset):
return self.__ter(fset, 1)
def deleter(self, fdel):
return self.__ter(fdel, 2)
def __ter(self, f, arg):
args = [self._fget, self._fset, self._fdel, self.__doc__]
args[arg] = f
cls_ns = sys._getframe(1).f_locals
for k, v in iteritems(cls_ns):
if v is self:
property_name = k
break
cls_ns[property_name] = lazyproperty(*args)
return cls_ns[property_name]
class PyfitsDeprecationWarning(UserWarning):
pass
class PyfitsPendingDeprecationWarning(UserWarning):
pass
# TODO: Provide a class deprecation marker as well.
def deprecated(since, message='', name='', alternative='', pending=False):
"""
Used to mark a function as deprecated.
To mark an attribute as deprecated, replace that attribute with a
depcrecated property.
Parameters
------------
since : str
The release at which this API became deprecated. This is required.
message : str, optional
Override the default deprecation message. The format specifier
%(func)s may be used for the name of the function, and %(alternative)s
may be used in the deprecation message to insert the name of an
alternative to the deprecated function.
name : str, optional
The name of the deprecated function; if not provided the name is
automatically determined from the passed in function, though this is
useful in the case of renamed functions, where the new function is just
assigned to the name of the deprecated function. For example:
def new_function():
...
oldFunction = new_function
alternative : str, optional
An alternative function that the user may use in place of the
deprecated function. The deprecation warning will tell the user about
this alternative if provided.
pending : bool, optional
If True, uses a PyfitsPendingDeprecationWarning instead of a
PyfitsDeprecationWarning.
"""
def deprecate(func, message=message, name=name, alternative=alternative,
pending=pending):
if isinstance(func, classmethod):
try:
func = func.__func__
except AttributeError:
# classmethods in Python2.6 and below lack the __func__
# attribute so we need to hack around to get it
method = func.__get__(None, object)
if hasattr(method, '__func__'):
func = method.__func__
elif hasattr(method, 'im_func'):
func = method.im_func
else:
# Nothing we can do really... just return the original
# classmethod
return func
is_classmethod = True
else:
is_classmethod = False
if not name:
name = func.__name__
altmessage = ''
if not message or type(message) == type(deprecate):
if pending:
message = ('The %(func)s function will be deprecated in a '
'future version.')
else:
message = (
'The %(func)s function is deprecated as of version '
'%(since)s and may be removed in a future version.')
if alternative:
altmessage = '\n\n Use %s instead.' % alternative
message = ((message % {'func': name, 'alternative': alternative,
'since': since}) + altmessage)
@functools.wraps(func)
def deprecated_func(*args, **kwargs):
if pending:
category = PyfitsPendingDeprecationWarning
else:
category = PyfitsDeprecationWarning
warnings.warn(message, category, stacklevel=2)
return func(*args, **kwargs)
old_doc = deprecated_func.__doc__
if not old_doc:
old_doc = ''
old_doc = textwrap.dedent(old_doc).strip('\n')
altmessage = altmessage.strip()
if not altmessage:
altmessage = message.strip()
new_doc = (('\n.. deprecated:: %(since)s'
'\n %(message)s\n\n' %
{'since': since, 'message': altmessage.strip()}) + old_doc)
if not old_doc:
# This is to prevent a spurious 'unexected unindent' warning from
# docutils when the original docstring was blank.
new_doc += r'\ '
deprecated_func.__doc__ = new_doc
if is_classmethod:
deprecated_func = classmethod(deprecated_func)
return deprecated_func
if type(message) == type(deprecate):
return deprecate(message)
return deprecate
def ignore_sigint(func):
"""
This decorator registers a custom SIGINT handler to catch and ignore SIGINT
until the wrapped function is completed.
"""
@functools.wraps(func)
def wrapped(*args, **kwargs):
# Get the name of the current thread and determine if this is a single
# treaded application
curr_thread = threading.currentThread()
single_thread = (threading.activeCount() == 1 and
curr_thread.getName() == 'MainThread')
class SigintHandler(object):
def __init__(self):
self.sigint_received = False
def __call__(self, signum, frame):
warnings.warn('KeyboardInterrupt ignored until %s is '
'complete!' % func.__name__)
self.sigint_received = True
sigint_handler = SigintHandler()
# Define new signal interput handler
if single_thread:
# Install new handler
old_handler = signal.signal(signal.SIGINT, sigint_handler)
try:
func(*args, **kwargs)
finally:
if single_thread:
if old_handler is not None:
signal.signal(signal.SIGINT, old_handler)
else:
signal.signal(signal.SIGINT, signal.SIG_DFL)
if sigint_handler.sigint_received:
raise KeyboardInterrupt
return wrapped
def pairwise(iterable):
"""Return the items of an iterable paired with its next item.
Ex: s -> (s0,s1), (s1,s2), (s2,s3), ....
"""
a, b = itertools.tee(iterable)
for _ in b:
# Just a little trick to advance b without having to catch
# StopIter if b happens to be empty
break
return zip(a, b)
def isiterable(obj):
"""Returns true of the given object is iterable."""
# In Python2.6 and up this is simply a matter of checking isinstance
# collections.Iterable, but this unavailable in Python 2.5 and below
try:
from collections import Iterable
if isinstance(obj, Iterable):
return True
except ImportError:
pass
try:
iter(obj)
return True
except TypeError:
return False
def encode_ascii(s):
"""
In Python 2 this is a no-op. Strings are left alone. In Python 3 this
will be replaced with a function that actually encodes unicode strings to
ASCII bytes.
"""
return s
def decode_ascii(s):
"""
In Python 2 this is a no-op. Strings are left alone. In Python 3 this
will be replaced with a function that actually decodes ascii bytes to
unicode.
"""
return s
def isreadable(f):
"""
Returns True if the file-like object can be read from. This is a common-
sense approximation of io.IOBase.readable.
"""
if hasattr(f, 'closed') and f.closed:
# This mimics the behavior of io.IOBase.readable
raise ValueError('I/O operation on closed file')
if not hasattr(f, 'read'):
return False
if hasattr(f, 'mode') and not any((c in f.mode for c in 'r+')):
return False
# Not closed, has a 'read()' method, and either has no known mode or a
# readable mode--should be good enough to assume 'readable'
return True
def iswritable(f):
"""
Returns True if the file-like object can be written to. This is a common-
sense approximation of io.IOBase.writable.
"""
if hasattr(f, 'closed') and f.closed:
# This mimics the behavior of io.IOBase.writable
raise ValueError('I/O operation on closed file')
if not hasattr(f, 'write'):
return False
if hasattr(f, 'mode') and not any((c in f.mode for c in 'wa+')):
return False
# Note closed, has a 'write()' method, and either has no known mode or a
# mode that supports writing--should be good enough to assume 'writable'
return True
def isfile(f):
"""
Returns True if the given object represents an OS-level file (that is,
isinstance(f, file)).
On Python 3 this also returns True if the given object is higher level
wrapper on top of a FileIO object, such as a TextIOWrapper.
"""
return isinstance(f, file)
def fileobj_open(filename, mode):
"""
A wrapper around the `open()` builtin.
This exists because in Python 3, `open()` returns an `io.BufferedReader` by
default. This is bad, because `io.BufferedReader` doesn't support random
access, which we need in some cases. In the Python 3 case (implemented in
the py3compat module) we must call open with buffering=0 to get a raw
random-access file reader.
"""
return open(filename, mode)
def fileobj_name(f):
"""
Returns the 'name' of file-like object f, if it has anything that could be
called its name. Otherwise f's class or type is returned. If f is a
string f itself is returned.
"""
if isinstance(f, string_types):
return f
elif hasattr(f, 'name'):
return f.name
elif hasattr(f, 'filename'):
return f.filename
elif hasattr(f, '__class__'):
return str(f.__class__)
else:
return str(type(f))
def fileobj_closed(f):
"""
Returns True if the given file-like object is closed or if f is not a
file-like object.
"""
if hasattr(f, 'closed'):
return f.closed
elif hasattr(f, 'fileobj') and hasattr(f.fileobj, 'closed'):
return f.fileobj.closed
elif hasattr(f, 'fp') and hasattr(f.fp, 'closed'):
return f.fp.closed
else:
return False
def fileobj_mode(f):
"""
Returns the 'mode' string of a file-like object if such a thing exists.
Otherwise returns None.
"""
# Go from most to least specific--for example gzip objects have a 'mode'
# attribute, but it's not analogous to the file.mode attribute
if hasattr(f, 'fileobj') and hasattr(f.fileobj, 'mode'):
fileobj = f.fileobj
elif hasattr(f, 'fp') and hasattr(f.fp, 'mode'):
fileobj = f.fp
elif hasattr(f, 'mode'):
fileobj = f
else:
return None
return _fileobj_normalize_mode(fileobj)
def _fileobj_normalize_mode(f):
"""Takes care of some corner cases in Python where the mode string
is either oddly formatted or does not truly represent the file mode.
"""
# I've noticed that sometimes Python can produce modes like 'r+b' which I
# would consider kind of a bug--mode strings should be normalized. Let's
# normalize it for them:
mode = f.mode
if isinstance(f, gzip.GzipFile):
# GzipFiles can be either readonly or writeonly
if mode == gzip.READ:
return 'rb'
elif mode == gzip.WRITE:
return 'wb'
else:
# This shouldn't happen?
return None
if '+' in mode:
mode = mode.replace('+', '')
mode += '+'
if _fileobj_is_append_mode(f) and 'a' not in mode:
mode = mode.replace('r', 'a').replace('w', 'a')
return mode
def _fileobj_is_append_mode(f):
"""Normally the way to tell if a file is in append mode is if it has
'a' in the mode string. However on Python 3 (or in particular with
the io module) this can't be relied on. See
http://bugs.python.org/issue18876.
"""
if 'a' in f.mode:
# Take care of the obvious case first
return True
# We might have an io.FileIO in which case the only way to know for sure
# if the file is in append mode is to ask the file descriptor
if not hasattr(f, 'fileno'):
# Who knows what this is?
return False
# Call platform-specific _is_append_mode
# If this file is already closed this can result in an error
try:
return _is_append_mode_platform(f.fileno())
except (ValueError, IOError):
return False
if sys.platform.startswith('win32'):
# This global variable is used in _is_append_mode to cache the computed
# size of the ioinfo struct from msvcrt which may have a different size
# depending on the version of the library and how it was compiled
_sizeof_ioinfo = None
def _make_is_append_mode():
# We build the platform-specific _is_append_mode function for Windows
# inside a function factory in order to avoid cluttering the local
# namespace with ctypes stuff
from ctypes import (cdll, c_size_t, c_void_p, c_int, c_char,
Structure, POINTER, cast)
try:
from ctypes.util import find_msvcrt
except ImportError:
# find_msvcrt is not available on Python 2.5 so we have to provide
# it ourselves anyways
from distutils.msvccompiler import get_build_version
def find_msvcrt():
version = get_build_version()
if version is None:
# better be safe than sorry
return None
if version <= 6:
clibname = 'msvcrt'
else:
clibname = 'msvcr%d' % (version * 10)
# If python was built with in debug mode
import imp
if imp.get_suffixes()[0][0] == '_d.pyd':
clibname += 'd'
return clibname+'.dll'
def _dummy_is_append_mode(fd):
warnings.warn(
'Could not find appropriate MS Visual C Runtime '
'library or library is corrupt/misconfigured; cannot '
'determine whether your file object was opened in append '
'mode. Please consider using a file object opened in write '
'mode instead.')
return False
msvcrt_dll = find_msvcrt()
if msvcrt_dll is None:
# If for some reason the C runtime can't be located then we're dead
# in the water. Just return a dummy function
return _dummy_is_append_mode
msvcrt = cdll.LoadLibrary(msvcrt_dll)
# Constants
IOINFO_L2E = 5
IOINFO_ARRAY_ELTS = 1 << IOINFO_L2E
IOINFO_ARRAYS = 64
FAPPEND = 0x20
_NO_CONSOLE_FILENO = -2
# Types
intptr_t = POINTER(c_int)
class my_ioinfo(Structure):
_fields_ = [('osfhnd', intptr_t),
('osfile', c_char)]
# Functions
_msize = msvcrt._msize
_msize.argtypes = (c_void_p,)
_msize.restype = c_size_t
# Variables
# Since we don't know how large the ioinfo struct is just treat the
# __pioinfo array as an array of byte pointers
__pioinfo = cast(msvcrt.__pioinfo, POINTER(POINTER(c_char)))
# Determine size of the ioinfo struct; see the comment above where
# _sizeof_ioinfo = None is set
global _sizeof_ioinfo
if __pioinfo[0] is not None:
_sizeof_ioinfo = _msize(__pioinfo[0]) // IOINFO_ARRAY_ELTS
if not _sizeof_ioinfo:
# This shouldn't happen, but I suppose it could if one is using a
# broken msvcrt, or just happened to have a dll of the same name
# lying around.
return _dummy_is_append_mode
def _is_append_mode(fd):
global _sizeof_ioinfo
if fd != _NO_CONSOLE_FILENO:
idx1 = fd >> IOINFO_L2E # The index into the __pioinfo array
# The n-th ioinfo pointer in __pioinfo[idx1]
idx2 = fd & ((1 << IOINFO_L2E) - 1)
if 0 <= idx1 < IOINFO_ARRAYS and __pioinfo[idx1] is not None:
# Doing pointer arithmetic in ctypes is irritating
pio = c_void_p(cast(__pioinfo[idx1], c_void_p).value +
idx2 * _sizeof_ioinfo)
ioinfo = cast(pio, POINTER(my_ioinfo)).contents
return bool(ord(ioinfo.osfile) & FAPPEND)
return False
return _is_append_mode
_is_append_mode_platform = _make_is_append_mode()
del _make_is_append_mode
else:
import fcntl
def _is_append_mode_platform(fd):
return bool(fcntl.fcntl(fd, fcntl.F_GETFL) & os.O_APPEND)
def fileobj_is_binary(f):
"""
Returns True if the give file or file-like object has a file open in binary
mode. When in doubt, returns True by default.
"""
# This is kind of a hack for this to work correctly with _File objects,
# which, for the time being, are *always* binary
if hasattr(f, 'binary'):
return f.binary
if io is not None and isinstance(f, io.TextIOBase):
return False
mode = fileobj_mode(f)
if mode:
return 'b' in mode
else:
return True
def translate(s, table, deletechars):
"""
This is a version of string/unicode.translate() that can handle string or
unicode strings the same way using a translation table made with
string.maketrans.
"""
if isinstance(s, str):
return s.translate(table, deletechars)
elif isinstance(s, text_type):
table = dict((x, ord(table[x])) for x in range(256)
if ord(table[x]) != x)
for c in deletechars:
table[ord(c)] = None
return s.translate(table)
def indent(s, shift=1, width=4):
indented = '\n'.join(' ' * (width * shift) + l if l else ''
for l in s.splitlines())
if s[-1] == '\n':
indented += '\n'
return indented
def fill(text, width, *args, **kwargs):
"""
Like :func:`textwrap.wrap` but preserves existing paragraphs which
:func:`textwrap.wrap` does not otherwise handle well. Also handles section
headers.
"""
paragraphs = text.split('\n\n')
def maybe_fill(t):
if all(len(l) < width for l in t.splitlines()):
return t
else:
return textwrap.fill(t, width, *args, **kwargs)
return '\n\n'.join(maybe_fill(p) for p in paragraphs)
def _array_from_file(infile, dtype, count, sep):
"""Create a numpy array from a file or a file-like object."""
if isfile(infile):
return np.fromfile(infile, dtype=dtype, count=count, sep=sep)
else:
# treat as file-like object with "read" method; this includes gzip file
# objects, because numpy.fromfile just reads the compressed bytes from
# their underlying file object, instead of the decompresed bytes
read_size = np.dtype(dtype).itemsize * count
s = infile.read(read_size)
return np.fromstring(s, dtype=dtype, count=count, sep=sep)
def _array_to_file(arr, outfile):
"""Write a numpy array to a file or a file-like object."""
if isfile(outfile):
def write(a, f):
a.tofile(f)
else:
# treat as file-like object with "write" method and write the array
# via its buffer interface
def write(a, f):
# StringIO in Python 2.5 asks 'if not s' which fails for a Numpy
# array; test ahead of time if the array is empty, and pass in the
# array buffer directly
if isinstance(f, StringIO):
if len(a):
f.write(a.data)
else:
f.write(a)
# Implements a workaround for a bug deep in OSX's stdlib file writing
# functions; on 64-bit OSX it is not possible to correctly write a number
# of bytes greater than 2 ** 32 and divisble by 4096 (or possibly 8192--
# whatever the default blocksize for the filesystem is).
# This issue should have a workaround in Numpy too, but hasn't been
# implemented there yet: https://github.com/astropy/astropy/issues/839
osx_write_limit = (2 ** 32) - 1
if (sys.platform == 'darwin' and arr.nbytes >= osx_write_limit + 1 and
arr.nbytes % 4096 == 0):
idx = 0
# chunksize is a count of elements in the array, not bytes
chunksize = osx_write_limit // arr.itemsize
while idx < arr.nbytes:
write(arr[idx:idx + chunksize], outfile)
idx += chunksize
else:
write(arr, outfile)
def _write_string(f, s):
"""
Write a string to a file, encoding to ASCII if the file is open in binary
mode, or decoding if the file is open in text mode.
"""
# Assume if the file object doesn't have a specific mode, that the mode is
# binary
binmode = fileobj_is_binary(f)
if binmode and isinstance(s, text_type):
s = encode_ascii(s)
elif not binmode and not isinstance(f, text_type):
s = decode_ascii(s)
elif isinstance(f, StringIO) and isinstance(s, np.ndarray):
# Workaround for StringIO/ndarray incompatibility
s = s.data
f.write(s)
def _convert_array(array, dtype):
"""
Converts an array to a new dtype--if the itemsize of the new dtype is
the same as the old dtype and both types are not numeric, a view is
returned. Otherwise a new array must be created.
"""
if array.dtype == dtype:
return array
elif (array.dtype.itemsize == dtype.itemsize and not
(np.issubdtype(array.dtype, np.number) and
np.issubdtype(dtype, np.number))):
# Includes a special case when both dtypes are at least numeric to
# account for ticket #218: https://aeon.stsci.edu/ssb/trac/pyfits/ticket/218
return array.view(dtype)
else:
return array.astype(dtype)
def _unsigned_zero(dtype):
"""
Given a numpy dtype, finds its "zero" point, which is exactly in the
middle of its range.
"""
assert dtype.kind == 'u'
return 1 << (dtype.itemsize * 8 - 1)
def _is_pseudo_unsigned(dtype):
return dtype.kind == 'u' and dtype.itemsize >= 2
def _is_int(val):
return isinstance(val, integer_types + (np.integer,))
def _str_to_num(val):
"""Converts a given string to either an int or a float if necessary."""
try:
num = int(val)
except ValueError:
# If this fails then an exception should be raised anyways
num = float(val)
return num
def _pad_length(stringlen):
"""Bytes needed to pad the input stringlen to the next FITS block."""
return (BLOCK_SIZE - (stringlen % BLOCK_SIZE)) % BLOCK_SIZE
def _normalize_slice(input, naxis):
"""
Set the slice's start/stop in the regular range.
"""
def _normalize(indx, npts):
if indx < -npts:
indx = 0
elif indx < 0:
indx += npts
elif indx > npts:
indx = npts
return indx
_start = input.start
if _start is None:
_start = 0
elif _is_int(_start):
_start = _normalize(_start, naxis)
else:
raise IndexError('Illegal slice %s; start must be integer.' % input)
_stop = input.stop
if _stop is None:
_stop = naxis
elif _is_int(_stop):
_stop = _normalize(_stop, naxis)
else:
raise IndexError('Illegal slice %s; stop must be integer.' % input)
if _stop < _start:
raise IndexError('Illegal slice %s; stop < start.' % input)
_step = input.step
if _step is None:
_step = 1
elif _is_int(_step):
if _step <= 0:
raise IndexError('Illegal slice %s; step must be positive.'
% input)
else:
raise IndexError('Illegal slice %s; step must be integer.' % input)
return slice(_start, _stop, _step)
def _words_group(input, strlen):
"""
Split a long string into parts where each part is no longer
than `strlen` and no word is cut into two pieces. But if
there is one single word which is longer than `strlen`, then
it will be split in the middle of the word.
"""
words = []
nblanks = input.count(' ')
nmax = max(nblanks, len(input) // strlen + 1)
arr = np.fromstring((input + ' '), dtype=(binary_type, 1))
# locations of the blanks
blank_loc = np.nonzero(arr == ' '.encode('latin1'))[0]
offset = 0
xoffset = 0
for idx in range(nmax):
try:
loc = np.nonzero(blank_loc >= strlen + offset)[0][0]
offset = blank_loc[loc - 1] + 1
if loc == 0:
offset = -1
except:
offset = len(input)
# check for one word longer than strlen, break in the middle
if offset <= xoffset:
offset = xoffset + strlen
# collect the pieces in a list
words.append(input[xoffset:offset])
if len(input) == offset:
break
xoffset = offset
return words
def _tmp_name(input):
"""
Create a temporary file name which should not already exist. Use the
directory of the input file as the base name of the mkstemp() output.
"""
if input is not None:
input = os.path.dirname(input)
f, fn = tempfile.mkstemp(dir=input)
os.close(f)
return fn
if sys.version_info[:2] < (2, 6):
# In Python 2.5 mmap.mmap is a function that returns an object of type
# 'mmap.mmap', but the mmap.mmap type is otherwise not accessible through
# the module
def _is_mmap(obj):
return (type(obj).__module__ == 'mmap' and
type(obj).__name__ == 'mmap')
else:
def _is_mmap(obj):
return isinstance(obj, mmap.mmap)
def _get_array_mmap(array):
"""
If the array has an mmap.mmap at base of its base chain, return the mmap
object; otherwise return None.
"""
if _is_mmap(array):
return array
base = array
while hasattr(base, 'base') and base.base is not None:
if _is_mmap(base.base):
return base.base
base = base.base
if sys.version_info[:2] < (2, 6):
import __builtin__
# Replace the builtin property to add support for the getter/setter/deleter
# mechanism as introduced in Python 2.6 (this can go away if we ever drop
# 2.5 support)
class property(property):
def __init__(self, fget, *args, **kwargs):
self.__doc__ = fget.__doc__
super(property, self).__init__(fget, *args, **kwargs)
def getter(self, fget):
return self.__ter(fget, 0)
def setter(self, fset):
return self.__ter(fset, 1)
def deleter(self, fdel):
return self.__ter(fdel, 2)
def __ter(self, f, arg):
args = [self.fget, self.fset, self.fdel, self.__doc__]
args[arg] = f
cls_ns = sys._getframe(1).f_locals
for k, v in iteritems(cls_ns):
if v is self:
property_name = k
break
cls_ns[property_name] = property(*args)
return cls_ns[property_name]
__builtin__.property = property
# Provide an implementation of izip_longest
class ZipExhausted(Exception):
pass
def izip_longest(*args, **kwds):
# izip_longest('ABCD', 'xy', fillvalue='-') --> Ax By C- D-
fillvalue = kwds.get('fillvalue')
counter = [len(args) - 1]
def sentinel():
if not counter[0]:
raise ZipExhausted
counter[0] -= 1
yield fillvalue
fillers = itertools.repeat(fillvalue)
iterators = [itertools.chain(it, sentinel(), fillers) for it in args]
try:
while iterators:
yield tuple(map(next, iterators))
except ZipExhausted:
pass
from .extern import six
six.moves.zip_longest = izip_longest
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