936 lines
28 KiB
Python
936 lines
28 KiB
Python
"""
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A place for internal code
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Some things are more easily handled Python.
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"""
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import ast
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import re
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import sys
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import warnings
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from ..exceptions import DTypePromotionError
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from .multiarray import dtype, array, ndarray, promote_types
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try:
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import ctypes
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except ImportError:
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ctypes = None
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IS_PYPY = sys.implementation.name == 'pypy'
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if sys.byteorder == 'little':
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_nbo = '<'
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else:
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_nbo = '>'
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def _makenames_list(adict, align):
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allfields = []
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for fname, obj in adict.items():
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n = len(obj)
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if not isinstance(obj, tuple) or n not in (2, 3):
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raise ValueError("entry not a 2- or 3- tuple")
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if n > 2 and obj[2] == fname:
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continue
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num = int(obj[1])
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if num < 0:
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raise ValueError("invalid offset.")
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format = dtype(obj[0], align=align)
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if n > 2:
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title = obj[2]
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else:
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title = None
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allfields.append((fname, format, num, title))
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# sort by offsets
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allfields.sort(key=lambda x: x[2])
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names = [x[0] for x in allfields]
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formats = [x[1] for x in allfields]
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offsets = [x[2] for x in allfields]
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titles = [x[3] for x in allfields]
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return names, formats, offsets, titles
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# Called in PyArray_DescrConverter function when
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# a dictionary without "names" and "formats"
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# fields is used as a data-type descriptor.
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def _usefields(adict, align):
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try:
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names = adict[-1]
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except KeyError:
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names = None
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if names is None:
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names, formats, offsets, titles = _makenames_list(adict, align)
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else:
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formats = []
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offsets = []
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titles = []
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for name in names:
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res = adict[name]
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formats.append(res[0])
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offsets.append(res[1])
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if len(res) > 2:
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titles.append(res[2])
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else:
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titles.append(None)
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return dtype({"names": names,
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"formats": formats,
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"offsets": offsets,
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"titles": titles}, align)
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# construct an array_protocol descriptor list
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# from the fields attribute of a descriptor
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# This calls itself recursively but should eventually hit
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# a descriptor that has no fields and then return
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# a simple typestring
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def _array_descr(descriptor):
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fields = descriptor.fields
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if fields is None:
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subdtype = descriptor.subdtype
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if subdtype is None:
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if descriptor.metadata is None:
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return descriptor.str
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else:
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new = descriptor.metadata.copy()
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if new:
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return (descriptor.str, new)
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else:
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return descriptor.str
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else:
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return (_array_descr(subdtype[0]), subdtype[1])
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names = descriptor.names
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ordered_fields = [fields[x] + (x,) for x in names]
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result = []
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offset = 0
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for field in ordered_fields:
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if field[1] > offset:
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num = field[1] - offset
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result.append(('', f'|V{num}'))
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offset += num
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elif field[1] < offset:
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raise ValueError(
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"dtype.descr is not defined for types with overlapping or "
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"out-of-order fields")
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if len(field) > 3:
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name = (field[2], field[3])
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else:
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name = field[2]
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if field[0].subdtype:
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tup = (name, _array_descr(field[0].subdtype[0]),
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field[0].subdtype[1])
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else:
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tup = (name, _array_descr(field[0]))
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offset += field[0].itemsize
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result.append(tup)
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if descriptor.itemsize > offset:
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num = descriptor.itemsize - offset
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result.append(('', f'|V{num}'))
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return result
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# Build a new array from the information in a pickle.
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# Note that the name numpy.core._internal._reconstruct is embedded in
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# pickles of ndarrays made with NumPy before release 1.0
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# so don't remove the name here, or you'll
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# break backward compatibility.
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def _reconstruct(subtype, shape, dtype):
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return ndarray.__new__(subtype, shape, dtype)
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# format_re was originally from numarray by J. Todd Miller
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format_re = re.compile(r'(?P<order1>[<>|=]?)'
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r'(?P<repeats> *[(]?[ ,0-9]*[)]? *)'
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r'(?P<order2>[<>|=]?)'
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r'(?P<dtype>[A-Za-z0-9.?]*(?:\[[a-zA-Z0-9,.]+\])?)')
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sep_re = re.compile(r'\s*,\s*')
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space_re = re.compile(r'\s+$')
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# astr is a string (perhaps comma separated)
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_convorder = {'=': _nbo}
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def _commastring(astr):
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startindex = 0
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result = []
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while startindex < len(astr):
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mo = format_re.match(astr, pos=startindex)
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try:
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(order1, repeats, order2, dtype) = mo.groups()
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except (TypeError, AttributeError):
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raise ValueError(
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f'format number {len(result)+1} of "{astr}" is not recognized'
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) from None
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startindex = mo.end()
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# Separator or ending padding
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if startindex < len(astr):
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if space_re.match(astr, pos=startindex):
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startindex = len(astr)
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else:
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mo = sep_re.match(astr, pos=startindex)
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if not mo:
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raise ValueError(
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'format number %d of "%s" is not recognized' %
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(len(result)+1, astr))
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startindex = mo.end()
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if order2 == '':
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order = order1
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elif order1 == '':
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order = order2
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else:
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order1 = _convorder.get(order1, order1)
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order2 = _convorder.get(order2, order2)
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if (order1 != order2):
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raise ValueError(
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'inconsistent byte-order specification %s and %s' %
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(order1, order2))
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order = order1
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if order in ('|', '=', _nbo):
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order = ''
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dtype = order + dtype
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if (repeats == ''):
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newitem = dtype
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else:
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newitem = (dtype, ast.literal_eval(repeats))
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result.append(newitem)
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return result
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class dummy_ctype:
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def __init__(self, cls):
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self._cls = cls
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def __mul__(self, other):
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return self
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def __call__(self, *other):
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return self._cls(other)
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def __eq__(self, other):
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return self._cls == other._cls
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def __ne__(self, other):
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return self._cls != other._cls
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def _getintp_ctype():
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val = _getintp_ctype.cache
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if val is not None:
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return val
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if ctypes is None:
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import numpy as np
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val = dummy_ctype(np.intp)
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else:
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char = dtype('p').char
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if char == 'i':
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val = ctypes.c_int
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elif char == 'l':
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val = ctypes.c_long
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elif char == 'q':
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val = ctypes.c_longlong
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else:
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val = ctypes.c_long
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_getintp_ctype.cache = val
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return val
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_getintp_ctype.cache = None
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# Used for .ctypes attribute of ndarray
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class _missing_ctypes:
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def cast(self, num, obj):
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return num.value
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class c_void_p:
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def __init__(self, ptr):
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self.value = ptr
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class _ctypes:
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def __init__(self, array, ptr=None):
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self._arr = array
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if ctypes:
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self._ctypes = ctypes
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self._data = self._ctypes.c_void_p(ptr)
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else:
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# fake a pointer-like object that holds onto the reference
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self._ctypes = _missing_ctypes()
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self._data = self._ctypes.c_void_p(ptr)
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self._data._objects = array
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if self._arr.ndim == 0:
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self._zerod = True
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else:
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self._zerod = False
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def data_as(self, obj):
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"""
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Return the data pointer cast to a particular c-types object.
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For example, calling ``self._as_parameter_`` is equivalent to
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``self.data_as(ctypes.c_void_p)``. Perhaps you want to use the data as a
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pointer to a ctypes array of floating-point data:
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``self.data_as(ctypes.POINTER(ctypes.c_double))``.
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The returned pointer will keep a reference to the array.
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"""
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# _ctypes.cast function causes a circular reference of self._data in
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# self._data._objects. Attributes of self._data cannot be released
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# until gc.collect is called. Make a copy of the pointer first then let
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# it hold the array reference. This is a workaround to circumvent the
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# CPython bug https://bugs.python.org/issue12836
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ptr = self._ctypes.cast(self._data, obj)
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ptr._arr = self._arr
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return ptr
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def shape_as(self, obj):
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"""
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Return the shape tuple as an array of some other c-types
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type. For example: ``self.shape_as(ctypes.c_short)``.
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"""
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if self._zerod:
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return None
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return (obj*self._arr.ndim)(*self._arr.shape)
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def strides_as(self, obj):
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"""
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Return the strides tuple as an array of some other
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c-types type. For example: ``self.strides_as(ctypes.c_longlong)``.
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"""
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if self._zerod:
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return None
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return (obj*self._arr.ndim)(*self._arr.strides)
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@property
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def data(self):
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"""
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A pointer to the memory area of the array as a Python integer.
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This memory area may contain data that is not aligned, or not in correct
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byte-order. The memory area may not even be writeable. The array
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flags and data-type of this array should be respected when passing this
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attribute to arbitrary C-code to avoid trouble that can include Python
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crashing. User Beware! The value of this attribute is exactly the same
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as ``self._array_interface_['data'][0]``.
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Note that unlike ``data_as``, a reference will not be kept to the array:
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code like ``ctypes.c_void_p((a + b).ctypes.data)`` will result in a
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pointer to a deallocated array, and should be spelt
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``(a + b).ctypes.data_as(ctypes.c_void_p)``
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"""
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return self._data.value
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@property
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def shape(self):
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"""
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(c_intp*self.ndim): A ctypes array of length self.ndim where
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the basetype is the C-integer corresponding to ``dtype('p')`` on this
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platform (see `~numpy.ctypeslib.c_intp`). This base-type could be
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`ctypes.c_int`, `ctypes.c_long`, or `ctypes.c_longlong` depending on
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the platform. The ctypes array contains the shape of
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the underlying array.
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"""
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return self.shape_as(_getintp_ctype())
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@property
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def strides(self):
|
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"""
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(c_intp*self.ndim): A ctypes array of length self.ndim where
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the basetype is the same as for the shape attribute. This ctypes array
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contains the strides information from the underlying array. This strides
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information is important for showing how many bytes must be jumped to
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get to the next element in the array.
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"""
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return self.strides_as(_getintp_ctype())
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|
|
@property
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def _as_parameter_(self):
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"""
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|
Overrides the ctypes semi-magic method
|
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Enables `c_func(some_array.ctypes)`
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"""
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return self.data_as(ctypes.c_void_p)
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|
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# Numpy 1.21.0, 2021-05-18
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def get_data(self):
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"""Deprecated getter for the `_ctypes.data` property.
|
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|
.. deprecated:: 1.21
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"""
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warnings.warn('"get_data" is deprecated. Use "data" instead',
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DeprecationWarning, stacklevel=2)
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return self.data
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|
|
def get_shape(self):
|
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"""Deprecated getter for the `_ctypes.shape` property.
|
|
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|
.. deprecated:: 1.21
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"""
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warnings.warn('"get_shape" is deprecated. Use "shape" instead',
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DeprecationWarning, stacklevel=2)
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return self.shape
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|
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def get_strides(self):
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"""Deprecated getter for the `_ctypes.strides` property.
|
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.. deprecated:: 1.21
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"""
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warnings.warn('"get_strides" is deprecated. Use "strides" instead',
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DeprecationWarning, stacklevel=2)
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return self.strides
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|
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def get_as_parameter(self):
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"""Deprecated getter for the `_ctypes._as_parameter_` property.
|
|
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.. deprecated:: 1.21
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"""
|
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warnings.warn(
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'"get_as_parameter" is deprecated. Use "_as_parameter_" instead',
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DeprecationWarning, stacklevel=2,
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)
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return self._as_parameter_
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|
|
|
|
def _newnames(datatype, order):
|
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"""
|
|
Given a datatype and an order object, return a new names tuple, with the
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order indicated
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"""
|
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oldnames = datatype.names
|
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nameslist = list(oldnames)
|
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if isinstance(order, str):
|
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order = [order]
|
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seen = set()
|
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if isinstance(order, (list, tuple)):
|
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for name in order:
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try:
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nameslist.remove(name)
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except ValueError:
|
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if name in seen:
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raise ValueError(f"duplicate field name: {name}") from None
|
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else:
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raise ValueError(f"unknown field name: {name}") from None
|
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seen.add(name)
|
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return tuple(list(order) + nameslist)
|
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raise ValueError(f"unsupported order value: {order}")
|
|
|
|
def _copy_fields(ary):
|
|
"""Return copy of structured array with padding between fields removed.
|
|
|
|
Parameters
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----------
|
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ary : ndarray
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Structured array from which to remove padding bytes
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|
Returns
|
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-------
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ary_copy : ndarray
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Copy of ary with padding bytes removed
|
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"""
|
|
dt = ary.dtype
|
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copy_dtype = {'names': dt.names,
|
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'formats': [dt.fields[name][0] for name in dt.names]}
|
|
return array(ary, dtype=copy_dtype, copy=True)
|
|
|
|
def _promote_fields(dt1, dt2):
|
|
""" Perform type promotion for two structured dtypes.
|
|
|
|
Parameters
|
|
----------
|
|
dt1 : structured dtype
|
|
First dtype.
|
|
dt2 : structured dtype
|
|
Second dtype.
|
|
|
|
Returns
|
|
-------
|
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out : dtype
|
|
The promoted dtype
|
|
|
|
Notes
|
|
-----
|
|
If one of the inputs is aligned, the result will be. The titles of
|
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both descriptors must match (point to the same field).
|
|
"""
|
|
# Both must be structured and have the same names in the same order
|
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if (dt1.names is None or dt2.names is None) or dt1.names != dt2.names:
|
|
raise DTypePromotionError(
|
|
f"field names `{dt1.names}` and `{dt2.names}` mismatch.")
|
|
|
|
# if both are identical, we can (maybe!) just return the same dtype.
|
|
identical = dt1 is dt2
|
|
new_fields = []
|
|
for name in dt1.names:
|
|
field1 = dt1.fields[name]
|
|
field2 = dt2.fields[name]
|
|
new_descr = promote_types(field1[0], field2[0])
|
|
identical = identical and new_descr is field1[0]
|
|
|
|
# Check that the titles match (if given):
|
|
if field1[2:] != field2[2:]:
|
|
raise DTypePromotionError(
|
|
f"field titles of field '{name}' mismatch")
|
|
if len(field1) == 2:
|
|
new_fields.append((name, new_descr))
|
|
else:
|
|
new_fields.append(((field1[2], name), new_descr))
|
|
|
|
res = dtype(new_fields, align=dt1.isalignedstruct or dt2.isalignedstruct)
|
|
|
|
# Might as well preserve identity (and metadata) if the dtype is identical
|
|
# and the itemsize, offsets are also unmodified. This could probably be
|
|
# sped up, but also probably just be removed entirely.
|
|
if identical and res.itemsize == dt1.itemsize:
|
|
for name in dt1.names:
|
|
if dt1.fields[name][1] != res.fields[name][1]:
|
|
return res # the dtype changed.
|
|
return dt1
|
|
|
|
return res
|
|
|
|
|
|
def _getfield_is_safe(oldtype, newtype, offset):
|
|
""" Checks safety of getfield for object arrays.
|
|
|
|
As in _view_is_safe, we need to check that memory containing objects is not
|
|
reinterpreted as a non-object datatype and vice versa.
|
|
|
|
Parameters
|
|
----------
|
|
oldtype : data-type
|
|
Data type of the original ndarray.
|
|
newtype : data-type
|
|
Data type of the field being accessed by ndarray.getfield
|
|
offset : int
|
|
Offset of the field being accessed by ndarray.getfield
|
|
|
|
Raises
|
|
------
|
|
TypeError
|
|
If the field access is invalid
|
|
|
|
"""
|
|
if newtype.hasobject or oldtype.hasobject:
|
|
if offset == 0 and newtype == oldtype:
|
|
return
|
|
if oldtype.names is not None:
|
|
for name in oldtype.names:
|
|
if (oldtype.fields[name][1] == offset and
|
|
oldtype.fields[name][0] == newtype):
|
|
return
|
|
raise TypeError("Cannot get/set field of an object array")
|
|
return
|
|
|
|
def _view_is_safe(oldtype, newtype):
|
|
""" Checks safety of a view involving object arrays, for example when
|
|
doing::
|
|
|
|
np.zeros(10, dtype=oldtype).view(newtype)
|
|
|
|
Parameters
|
|
----------
|
|
oldtype : data-type
|
|
Data type of original ndarray
|
|
newtype : data-type
|
|
Data type of the view
|
|
|
|
Raises
|
|
------
|
|
TypeError
|
|
If the new type is incompatible with the old type.
|
|
|
|
"""
|
|
|
|
# if the types are equivalent, there is no problem.
|
|
# for example: dtype((np.record, 'i4,i4')) == dtype((np.void, 'i4,i4'))
|
|
if oldtype == newtype:
|
|
return
|
|
|
|
if newtype.hasobject or oldtype.hasobject:
|
|
raise TypeError("Cannot change data-type for object array.")
|
|
return
|
|
|
|
# Given a string containing a PEP 3118 format specifier,
|
|
# construct a NumPy dtype
|
|
|
|
_pep3118_native_map = {
|
|
'?': '?',
|
|
'c': 'S1',
|
|
'b': 'b',
|
|
'B': 'B',
|
|
'h': 'h',
|
|
'H': 'H',
|
|
'i': 'i',
|
|
'I': 'I',
|
|
'l': 'l',
|
|
'L': 'L',
|
|
'q': 'q',
|
|
'Q': 'Q',
|
|
'e': 'e',
|
|
'f': 'f',
|
|
'd': 'd',
|
|
'g': 'g',
|
|
'Zf': 'F',
|
|
'Zd': 'D',
|
|
'Zg': 'G',
|
|
's': 'S',
|
|
'w': 'U',
|
|
'O': 'O',
|
|
'x': 'V', # padding
|
|
}
|
|
_pep3118_native_typechars = ''.join(_pep3118_native_map.keys())
|
|
|
|
_pep3118_standard_map = {
|
|
'?': '?',
|
|
'c': 'S1',
|
|
'b': 'b',
|
|
'B': 'B',
|
|
'h': 'i2',
|
|
'H': 'u2',
|
|
'i': 'i4',
|
|
'I': 'u4',
|
|
'l': 'i4',
|
|
'L': 'u4',
|
|
'q': 'i8',
|
|
'Q': 'u8',
|
|
'e': 'f2',
|
|
'f': 'f',
|
|
'd': 'd',
|
|
'Zf': 'F',
|
|
'Zd': 'D',
|
|
's': 'S',
|
|
'w': 'U',
|
|
'O': 'O',
|
|
'x': 'V', # padding
|
|
}
|
|
_pep3118_standard_typechars = ''.join(_pep3118_standard_map.keys())
|
|
|
|
_pep3118_unsupported_map = {
|
|
'u': 'UCS-2 strings',
|
|
'&': 'pointers',
|
|
't': 'bitfields',
|
|
'X': 'function pointers',
|
|
}
|
|
|
|
class _Stream:
|
|
def __init__(self, s):
|
|
self.s = s
|
|
self.byteorder = '@'
|
|
|
|
def advance(self, n):
|
|
res = self.s[:n]
|
|
self.s = self.s[n:]
|
|
return res
|
|
|
|
def consume(self, c):
|
|
if self.s[:len(c)] == c:
|
|
self.advance(len(c))
|
|
return True
|
|
return False
|
|
|
|
def consume_until(self, c):
|
|
if callable(c):
|
|
i = 0
|
|
while i < len(self.s) and not c(self.s[i]):
|
|
i = i + 1
|
|
return self.advance(i)
|
|
else:
|
|
i = self.s.index(c)
|
|
res = self.advance(i)
|
|
self.advance(len(c))
|
|
return res
|
|
|
|
@property
|
|
def next(self):
|
|
return self.s[0]
|
|
|
|
def __bool__(self):
|
|
return bool(self.s)
|
|
|
|
|
|
def _dtype_from_pep3118(spec):
|
|
stream = _Stream(spec)
|
|
dtype, align = __dtype_from_pep3118(stream, is_subdtype=False)
|
|
return dtype
|
|
|
|
def __dtype_from_pep3118(stream, is_subdtype):
|
|
field_spec = dict(
|
|
names=[],
|
|
formats=[],
|
|
offsets=[],
|
|
itemsize=0
|
|
)
|
|
offset = 0
|
|
common_alignment = 1
|
|
is_padding = False
|
|
|
|
# Parse spec
|
|
while stream:
|
|
value = None
|
|
|
|
# End of structure, bail out to upper level
|
|
if stream.consume('}'):
|
|
break
|
|
|
|
# Sub-arrays (1)
|
|
shape = None
|
|
if stream.consume('('):
|
|
shape = stream.consume_until(')')
|
|
shape = tuple(map(int, shape.split(',')))
|
|
|
|
# Byte order
|
|
if stream.next in ('@', '=', '<', '>', '^', '!'):
|
|
byteorder = stream.advance(1)
|
|
if byteorder == '!':
|
|
byteorder = '>'
|
|
stream.byteorder = byteorder
|
|
|
|
# Byte order characters also control native vs. standard type sizes
|
|
if stream.byteorder in ('@', '^'):
|
|
type_map = _pep3118_native_map
|
|
type_map_chars = _pep3118_native_typechars
|
|
else:
|
|
type_map = _pep3118_standard_map
|
|
type_map_chars = _pep3118_standard_typechars
|
|
|
|
# Item sizes
|
|
itemsize_str = stream.consume_until(lambda c: not c.isdigit())
|
|
if itemsize_str:
|
|
itemsize = int(itemsize_str)
|
|
else:
|
|
itemsize = 1
|
|
|
|
# Data types
|
|
is_padding = False
|
|
|
|
if stream.consume('T{'):
|
|
value, align = __dtype_from_pep3118(
|
|
stream, is_subdtype=True)
|
|
elif stream.next in type_map_chars:
|
|
if stream.next == 'Z':
|
|
typechar = stream.advance(2)
|
|
else:
|
|
typechar = stream.advance(1)
|
|
|
|
is_padding = (typechar == 'x')
|
|
dtypechar = type_map[typechar]
|
|
if dtypechar in 'USV':
|
|
dtypechar += '%d' % itemsize
|
|
itemsize = 1
|
|
numpy_byteorder = {'@': '=', '^': '='}.get(
|
|
stream.byteorder, stream.byteorder)
|
|
value = dtype(numpy_byteorder + dtypechar)
|
|
align = value.alignment
|
|
elif stream.next in _pep3118_unsupported_map:
|
|
desc = _pep3118_unsupported_map[stream.next]
|
|
raise NotImplementedError(
|
|
"Unrepresentable PEP 3118 data type {!r} ({})"
|
|
.format(stream.next, desc))
|
|
else:
|
|
raise ValueError("Unknown PEP 3118 data type specifier %r" % stream.s)
|
|
|
|
#
|
|
# Native alignment may require padding
|
|
#
|
|
# Here we assume that the presence of a '@' character implicitly implies
|
|
# that the start of the array is *already* aligned.
|
|
#
|
|
extra_offset = 0
|
|
if stream.byteorder == '@':
|
|
start_padding = (-offset) % align
|
|
intra_padding = (-value.itemsize) % align
|
|
|
|
offset += start_padding
|
|
|
|
if intra_padding != 0:
|
|
if itemsize > 1 or (shape is not None and _prod(shape) > 1):
|
|
# Inject internal padding to the end of the sub-item
|
|
value = _add_trailing_padding(value, intra_padding)
|
|
else:
|
|
# We can postpone the injection of internal padding,
|
|
# as the item appears at most once
|
|
extra_offset += intra_padding
|
|
|
|
# Update common alignment
|
|
common_alignment = _lcm(align, common_alignment)
|
|
|
|
# Convert itemsize to sub-array
|
|
if itemsize != 1:
|
|
value = dtype((value, (itemsize,)))
|
|
|
|
# Sub-arrays (2)
|
|
if shape is not None:
|
|
value = dtype((value, shape))
|
|
|
|
# Field name
|
|
if stream.consume(':'):
|
|
name = stream.consume_until(':')
|
|
else:
|
|
name = None
|
|
|
|
if not (is_padding and name is None):
|
|
if name is not None and name in field_spec['names']:
|
|
raise RuntimeError(f"Duplicate field name '{name}' in PEP3118 format")
|
|
field_spec['names'].append(name)
|
|
field_spec['formats'].append(value)
|
|
field_spec['offsets'].append(offset)
|
|
|
|
offset += value.itemsize
|
|
offset += extra_offset
|
|
|
|
field_spec['itemsize'] = offset
|
|
|
|
# extra final padding for aligned types
|
|
if stream.byteorder == '@':
|
|
field_spec['itemsize'] += (-offset) % common_alignment
|
|
|
|
# Check if this was a simple 1-item type, and unwrap it
|
|
if (field_spec['names'] == [None]
|
|
and field_spec['offsets'][0] == 0
|
|
and field_spec['itemsize'] == field_spec['formats'][0].itemsize
|
|
and not is_subdtype):
|
|
ret = field_spec['formats'][0]
|
|
else:
|
|
_fix_names(field_spec)
|
|
ret = dtype(field_spec)
|
|
|
|
# Finished
|
|
return ret, common_alignment
|
|
|
|
def _fix_names(field_spec):
|
|
""" Replace names which are None with the next unused f%d name """
|
|
names = field_spec['names']
|
|
for i, name in enumerate(names):
|
|
if name is not None:
|
|
continue
|
|
|
|
j = 0
|
|
while True:
|
|
name = f'f{j}'
|
|
if name not in names:
|
|
break
|
|
j = j + 1
|
|
names[i] = name
|
|
|
|
def _add_trailing_padding(value, padding):
|
|
"""Inject the specified number of padding bytes at the end of a dtype"""
|
|
if value.fields is None:
|
|
field_spec = dict(
|
|
names=['f0'],
|
|
formats=[value],
|
|
offsets=[0],
|
|
itemsize=value.itemsize
|
|
)
|
|
else:
|
|
fields = value.fields
|
|
names = value.names
|
|
field_spec = dict(
|
|
names=names,
|
|
formats=[fields[name][0] for name in names],
|
|
offsets=[fields[name][1] for name in names],
|
|
itemsize=value.itemsize
|
|
)
|
|
|
|
field_spec['itemsize'] += padding
|
|
return dtype(field_spec)
|
|
|
|
def _prod(a):
|
|
p = 1
|
|
for x in a:
|
|
p *= x
|
|
return p
|
|
|
|
def _gcd(a, b):
|
|
"""Calculate the greatest common divisor of a and b"""
|
|
while b:
|
|
a, b = b, a % b
|
|
return a
|
|
|
|
def _lcm(a, b):
|
|
return a // _gcd(a, b) * b
|
|
|
|
def array_ufunc_errmsg_formatter(dummy, ufunc, method, *inputs, **kwargs):
|
|
""" Format the error message for when __array_ufunc__ gives up. """
|
|
args_string = ', '.join(['{!r}'.format(arg) for arg in inputs] +
|
|
['{}={!r}'.format(k, v)
|
|
for k, v in kwargs.items()])
|
|
args = inputs + kwargs.get('out', ())
|
|
types_string = ', '.join(repr(type(arg).__name__) for arg in args)
|
|
return ('operand type(s) all returned NotImplemented from '
|
|
'__array_ufunc__({!r}, {!r}, {}): {}'
|
|
.format(ufunc, method, args_string, types_string))
|
|
|
|
|
|
def array_function_errmsg_formatter(public_api, types):
|
|
""" Format the error message for when __array_ufunc__ gives up. """
|
|
func_name = '{}.{}'.format(public_api.__module__, public_api.__name__)
|
|
return ("no implementation found for '{}' on types that implement "
|
|
'__array_function__: {}'.format(func_name, list(types)))
|
|
|
|
|
|
def _ufunc_doc_signature_formatter(ufunc):
|
|
"""
|
|
Builds a signature string which resembles PEP 457
|
|
|
|
This is used to construct the first line of the docstring
|
|
"""
|
|
|
|
# input arguments are simple
|
|
if ufunc.nin == 1:
|
|
in_args = 'x'
|
|
else:
|
|
in_args = ', '.join(f'x{i+1}' for i in range(ufunc.nin))
|
|
|
|
# output arguments are both keyword or positional
|
|
if ufunc.nout == 0:
|
|
out_args = ', /, out=()'
|
|
elif ufunc.nout == 1:
|
|
out_args = ', /, out=None'
|
|
else:
|
|
out_args = '[, {positional}], / [, out={default}]'.format(
|
|
positional=', '.join(
|
|
'out{}'.format(i+1) for i in range(ufunc.nout)),
|
|
default=repr((None,)*ufunc.nout)
|
|
)
|
|
|
|
# keyword only args depend on whether this is a gufunc
|
|
kwargs = (
|
|
", casting='same_kind'"
|
|
", order='K'"
|
|
", dtype=None"
|
|
", subok=True"
|
|
)
|
|
|
|
# NOTE: gufuncs may or may not support the `axis` parameter
|
|
if ufunc.signature is None:
|
|
kwargs = f", where=True{kwargs}[, signature, extobj]"
|
|
else:
|
|
kwargs += "[, signature, extobj, axes, axis]"
|
|
|
|
# join all the parts together
|
|
return '{name}({in_args}{out_args}, *{kwargs})'.format(
|
|
name=ufunc.__name__,
|
|
in_args=in_args,
|
|
out_args=out_args,
|
|
kwargs=kwargs
|
|
)
|
|
|
|
|
|
def npy_ctypes_check(cls):
|
|
# determine if a class comes from ctypes, in order to work around
|
|
# a bug in the buffer protocol for those objects, bpo-10746
|
|
try:
|
|
# ctypes class are new-style, so have an __mro__. This probably fails
|
|
# for ctypes classes with multiple inheritance.
|
|
if IS_PYPY:
|
|
# (..., _ctypes.basics._CData, Bufferable, object)
|
|
ctype_base = cls.__mro__[-3]
|
|
else:
|
|
# # (..., _ctypes._CData, object)
|
|
ctype_base = cls.__mro__[-2]
|
|
# right now, they're part of the _ctypes module
|
|
return '_ctypes' in ctype_base.__module__
|
|
except Exception:
|
|
return False
|