#A place for code to be called from C-code
# that implements more complicated stuff.
import re
import sys
if (sys.byteorder == 'little'):
_nbo = '<'
else:
_nbo = '>'
def _makenames_list(adict):
from multiarray import dtype
allfields = []
fnames = adict.keys()
for fname in fnames:
obj = adict[fname]
n = len(obj)
if not isinstance(obj, tuple) or n not in [2,3]:
raise ValueError, "entry not a 2- or 3- tuple"
if (n > 2) and (obj[2] == fname):
continue
num = int(obj[1])
if (num < 0):
raise ValueError, "invalid offset."
format = dtype(obj[0])
if (format.itemsize == 0):
raise ValueError, "all itemsizes must be fixed."
if (n > 2):
title = obj[2]
else:
title = None
allfields.append((fname, format, num, title))
# sort by offsets
allfields.sort(lambda x,y: cmp(x[2],y[2]))
names = [x[0] for x in allfields]
formats = [x[1] for x in allfields]
offsets = [x[2] for x in allfields]
titles = [x[3] for x in allfields]
return names, formats, offsets, titles
# Called in PyArray_DescrConverter function when
# a dictionary without "names" and "formats"
# fields is used as a data-type descriptor.
def _usefields(adict, align):
from multiarray import dtype
try:
names = adict[-1]
except KeyError:
names = None
if names is None:
names, formats, offsets, titles = _makenames_list(adict)
else:
formats = []
offsets = []
titles = []
for name in names:
res = adict[name]
formats.append(res[0])
offsets.append(res[1])
if (len(res) > 2):
titles.append(res[2])
else:
titles.append(None)
return dtype({"names" : names,
"formats" : formats,
"offsets" : offsets,
"titles" : titles}, align)
# construct an array_protocol descriptor list
# from the fields attribute of a descriptor
# This calls itself recursively but should eventually hit
# a descriptor that has no fields and then return
# a simple typestring
def _array_descr(descriptor):
fields = descriptor.fields
if fields is None:
subdtype = descriptor.subdtype
if subdtype is None:
return descriptor.str
else:
return (_array_descr(subdtype[0]), subdtype[1])
names = descriptor.names
ordered_fields = [fields[x] + (x,) for x in names]
result = []
offset = 0
for field in ordered_fields:
if field[1] > offset:
num = field[1] - offset
result.append(('','|V%d' % num))
offset += num
if len(field) > 3:
name = (field[2],field[3])
else:
name = field[2]
if field[0].subdtype:
tup = (name, _array_descr(field[0].subdtype[0]),
field[0].subdtype[1])
else:
tup = (name, _array_descr(field[0]))
offset += field[0].itemsize
result.append(tup)
return result
# Build a new array from the information in a pickle.
# Note that the name numpy.core._internal._reconstruct is embedded in
# pickles of ndarrays made with NumPy before release 1.0
# so don't remove the name here, or you'll
# break backward compatibilty.
def _reconstruct(subtype, shape, dtype):
from multiarray import ndarray
return ndarray.__new__(subtype, shape, dtype)
# format_re and _split were taken from numarray by J. Todd Miller
def _split(input):
"""Split the input formats string into field formats without splitting
the tuple used to specify multi-dimensional arrays."""
newlist = []
hold = ''
listinput = input.split(',')
for element in listinput:
if hold != '':
item = hold + ',' + element
else:
item = element
left = item.count('(')
right = item.count(')')
# if the parenthesis is not balanced, hold the string
if left > right :
hold = item
# when balanced, append to the output list and reset the hold
elif left == right:
newlist.append(item.strip())
hold = ''
# too many close parenthesis is unacceptable
else:
raise SyntaxError, item
# if there is string left over in hold
if hold != '':
raise SyntaxError, hold
return newlist
format_re = re.compile(r'(?P<order1>[<>|=]?)(?P<repeats> *[(]?[ ,0-9]*[)]? *)(?P<order2>[<>|=]?)(?P<dtype>[A-Za-z0-9.]*)')
# astr is a string (perhaps comma separated)
_convorder = {'=': _nbo,
'|': '|',
'>': '>',
'<': '<'}
def _commastring(astr):
res = _split(astr)
if (len(res)) < 1:
raise ValueError, "unrecognized formant"
result = []
for k,item in enumerate(res):
# convert item
try:
(order1, repeats, order2, dtype) = format_re.match(item).groups()
except (TypeError, AttributeError):
raise ValueError('format %s is not recognized' % item)
if order2 == '':
order = order1
elif order1 == '':
order = order2
else:
order1 = _convorder[order1]
order2 = _convorder[order2]
if (order1 != order2):
raise ValueError('in-consistent byte-order specification %s and %s' % (order1, order2))
order = order1
if order in ['|', '=', _nbo]:
order = ''
dtype = '%s%s' % (order, dtype)
if (repeats == ''):
newitem = dtype
else:
newitem = (dtype, eval(repeats))
result.append(newitem)
return result
def _getintp_ctype():
from multiarray import dtype
val = _getintp_ctype.cache
if val is not None:
return val
char = dtype('p').char
import ctypes
if (char == 'i'):
val = ctypes.c_int
elif char == 'l':
val = ctypes.c_long
elif char == 'q':
val = ctypes.c_longlong
else:
val = ctypes.c_long
_getintp_ctype.cache = val
return val
_getintp_ctype.cache = None
# Used for .ctypes attribute of ndarray
class _missing_ctypes(object):
def cast(self, num, obj):
return num
def c_void_p(self, num):
return num
class _ctypes(object):
def __init__(self, array, ptr=None):
try:
import ctypes
self._ctypes = ctypes
except ImportError:
self._ctypes = _missing_ctypes()
self._arr = array
self._data = ptr
if self._arr.ndim == 0:
self._zerod = True
else:
self._zerod = False
def data_as(self, obj):
return self._ctypes.cast(self._data, obj)
def shape_as(self, obj):
if self._zerod:
return None
return (obj*self._arr.ndim)(*self._arr.shape)
def strides_as(self, obj):
if self._zerod:
return None
return (obj*self._arr.ndim)(*self._arr.strides)
def get_data(self):
return self._data
def get_shape(self):
if self._zerod:
return None
return (_getintp_ctype()*self._arr.ndim)(*self._arr.shape)
def get_strides(self):
if self._zerod:
return None
return (_getintp_ctype()*self._arr.ndim)(*self._arr.strides)
def get_as_parameter(self):
return self._ctypes.c_void_p(self._data)
data = property(get_data, None, doc="c-types data")
shape = property(get_shape, None, doc="c-types shape")
strides = property(get_strides, None, doc="c-types strides")
_as_parameter_ = property(get_as_parameter, None, doc="_as parameter_")
# Given a datatype and an order object
# return a new names tuple
# with the order indicated
def _newnames(datatype, order):
oldnames = datatype.names
nameslist = list(oldnames)
if isinstance(order, str):
order = [order]
if isinstance(order, (list, tuple)):
for name in order:
try:
nameslist.remove(name)
except ValueError:
raise ValueError, "unknown field name: %s" % (name,)
return tuple(list(order) + nameslist)
raise ValueError, "unsupported order value: %s" % (order,)
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