def _add_trailing_padding(value, padding):
"""Inject the specified number of padding bytes at the end of a dtype"""
from numpy.core import dtype
if value.fields is None:
vfields = {'f0': (value, 0)}
else:
vfields = dict(value.fields)
if value.names and value.names[-1] == '' and \
value[''].char == 'V':
# A trailing padding field is already present
vfields[''] = ('V%d' % (vfields[''][0].itemsize + padding),
vfields[''][1])
value = dtype(vfields)
else:
# Get a free name for the padding field
j = 0
while True:
name = 'pad%d' % j
if name not in vfields:
vfields[name] = ('V%d' % padding, value.itemsize)
break
j += 1
value = dtype(vfields)
if '' not in vfields:
# Strip out the name of the padding field
names = list(value.names)
names[-1] = ''
value.names = tuple(names)
return value
def add_newdoc_for_scalar_type(obj, fixed_aliases, doc):
# note: `:field: value` is rST syntax which renders as field lists.
o = getattr(_numerictypes, obj)
character_code = dtype(o).char
canonical_name_doc = (
"" if obj == o.__name__ else ":Canonical name: `numpy.{}`\n ".format(obj)
)
alias_doc = "".join(
":Alias: `numpy.{}`\n ".format(alias) for alias in fixed_aliases
)
alias_doc += "".join(
":Alias on this platform: `numpy.{}`: {}.\n ".format(alias, doc)
for (alias_type, alias, doc) in possible_aliases
if alias_type is o
)
docstring = """
{doc}
:Character code: ``'{character_code}'``
{canonical_name_doc}{alias_doc}
""".format(
doc=doc.strip(),
character_code=character_code,
canonical_name_doc=canonical_name_doc,
alias_doc=alias_doc,
)
add_newdoc("numpy.core.numerictypes", obj, docstring)
def _usefields(adict, align):
from numpy.core 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)
def _makenames_list(adict):
from numpy.core 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(key=lambda x: x[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
def _getintp_ctype():
from numpy.core 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
def add_newdoc_for_scalar_type(obj, fixed_aliases, doc):
# note: `:field: value` is rST syntax which renders as field lists.
o = getattr(_numerictypes, obj)
character_code = dtype(o).char
canonical_name_doc = "" if obj == o.__name__ else \
f":Canonical name: `numpy.{obj}`\n "
if fixed_aliases:
alias_doc = ''.join(f":Alias: `numpy.{alias}`\n "
for alias in fixed_aliases)
else:
alias_doc = ''
alias_doc += ''.join(f"{_doc_alias_string} `numpy.{alias}`: {doc}.\n "
for (alias_type, alias, doc) in possible_aliases
if alias_type is o)
docstring = f"""
{doc.strip()}
:Character code: ``'{character_code}'``
{canonical_name_doc}{alias_doc}
"""
add_newdoc('numpy.core.numerictypes', obj, docstring)
def _dtype_from_pep3118(spec, byteorder='@', is_subdtype=False):
from numpy.core import dtype
fields = {}
offset = 0
explicit_name = False
this_explicit_name = False
common_alignment = 1
is_padding = False
last_offset = 0
dummy_name_index = [0]
def next_dummy_name():
dummy_name_index[0] += 1
def get_dummy_name():
while True:
name = 'f%d' % dummy_name_index[0]
if name not in fields:
return name
next_dummy_name()
# Parse spec
while spec:
value = None
# End of structure, bail out to upper level
if spec[0] == '}':
spec = spec[1:]
break
# Sub-arrays (1)
shape = None
if spec[0] == '(':
j = spec.index(')')
shape = tuple(map(int, spec[1:j].split(',')))
spec = spec[j+1:]
# Byte order
if spec[0] in ('@', '=', '<', '>', '^', '!'):
byteorder = spec[0]
if byteorder == '!':
byteorder = '>'
spec = spec[1:]
# Byte order characters also control native vs. standard type sizes
if 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 = 1
if spec[0].isdigit():
j = 1
for j in xrange(1, len(spec)):
if not spec[j].isdigit():
break
itemsize = int(spec[:j])
spec = spec[j:]
# Data types
is_padding = False
if spec[:2] == 'T{':
value, spec, align, next_byteorder = _dtype_from_pep3118(
spec[2:], byteorder=byteorder, is_subdtype=True)
elif spec[0] in type_map_chars:
next_byteorder = byteorder
if spec[0] == 'Z':
j = 2
else:
j = 1
typechar = spec[:j]
spec = spec[j:]
is_padding = (typechar == 'x')
dtypechar = type_map[typechar]
if dtypechar in 'USV':
dtypechar += '%d' % itemsize
itemsize = 1
numpy_byteorder = {'@': '=', '^': '='}.get(byteorder, byteorder)
value = dtype(numpy_byteorder + dtypechar)
align = value.alignment
else:
raise ValueError("Unknown PEP 3118 data type specifier %r" % spec)
#
# 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 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 = (align*common_alignment
/ _gcd(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
this_explicit_name = False
if spec and spec.startswith(':'):
i = spec[1:].index(':') + 1
name = spec[1:i]
spec = spec[i+1:]
explicit_name = True
this_explicit_name = True
else:
name = get_dummy_name()
if not is_padding or this_explicit_name:
if name in fields:
raise RuntimeError("Duplicate field name '%s' in PEP3118 format"
% name)
fields[name] = (value, offset)
last_offset = offset
if not this_explicit_name:
next_dummy_name()
byteorder = next_byteorder
offset += value.itemsize
offset += extra_offset
# Check if this was a simple 1-item type
if len(fields.keys()) == 1 and not explicit_name and fields['f0'][1] == 0 \
and not is_subdtype:
ret = fields['f0'][0]
else:
ret = dtype(fields)
# Trailing padding must be explicitly added
padding = offset - ret.itemsize
if byteorder == '@':
padding += (-offset) % common_alignment
if is_padding and not this_explicit_name:
ret = _add_trailing_padding(ret, padding)
# Finished
if is_subdtype:
return ret, spec, common_alignment, byteorder
else:
return ret
value, and ``False`` otherwise.
.. versionadded:: 1.22
Examples
--------
>>> np.{float_name}(-2.0).is_integer()
True
>>> np.{float_name}(3.2).is_integer()
False
"""))
for int_name in ('int8', 'uint8', 'int16', 'uint16', 'int32', 'uint32',
'int64', 'uint64', 'int64', 'uint64', 'int64', 'uint64'):
# Add negative examples for signed cases by checking typecode
add_newdoc('numpy.core.numerictypes', int_name, ('bit_count',
f"""
{int_name}.bit_count() -> int
Computes the number of 1-bits in the absolute value of the input.
Analogous to the builtin `int.bit_count` or ``popcount`` in C++.
Examples
--------
>>> np.{int_name}(127).bit_count()
7""" +
(f"""
>>> np.{int_name}(-127).bit_count()
7
""" if dtype(int_name).char.islower() else "")))
