numpy · mtsokol · Aug 13, 2023 · Aug 14, 2023 · Aug 29, 2023
diff --git a/numpy/core/_expired_type_aliases.py b/numpy/core/_expired_type_aliases.py
@@ -0,0 +1,243 @@
+"""
+Due to compatibility, numpy has a very large number of different naming
+conventions for the scalar types (those subclassing from `numpy.generic`).
+This file produces a convoluted set of dictionaries mapping names to types,
+and sometimes other mappings too.
+
+.. data:: allTypes
+    A dictionary of names to types that will be exposed as attributes through
+    ``np.core.numerictypes.*``
+
+.. data:: sctypeDict
+    Similar to `allTypes`, but maps a broader set of aliases to their types.
+
+.. data:: sctypes
+    A dictionary keyed by a "type group" string, providing a list of types
+    under that group.
+
+"""
+
+from numpy.core._string_helpers import english_lower
+from numpy.core.multiarray import typeinfo, dtype
+from numpy.core._dtype import _kind_name
+
+
+sctypeDict = {}      # Contains all leaf-node scalar types with aliases
+allTypes = {}            # Collect the types we will add to the module
+
+
+# separate the actual type info from the abstract base classes
+_abstract_types = {}
+_concrete_typeinfo = {}
+for k, v in typeinfo.items():
+    # make all the keys lowercase too
+    k = english_lower(k)
+    if isinstance(v, type):
+        _abstract_types[k] = v
+    else:
+        _concrete_typeinfo[k] = v
+
+_concrete_types = {v.type for k, v in _concrete_typeinfo.items()}
+
+
+def _bits_of(obj):
+    try:
+        info = next(v for v in _concrete_typeinfo.values() if v.type is obj)
+    except StopIteration:
+        if obj in _abstract_types.values():
+            msg = "Cannot count the bits of an abstract type"
+            raise ValueError(msg) from None
+
+        # some third-party type - make a best-guess
+        return dtype(obj).itemsize * 8
+    else:
+        return info.bits
+
+
+def bitname(obj):
+    """Return a bit-width name for a given type object"""
+    bits = _bits_of(obj)
+    dt = dtype(obj)
+    char = dt.kind
+    base = _kind_name(dt)
+
+    if base == 'object':
+        bits = 0
+
+    if bits != 0:
+        char = "%s%d" % (char, bits // 8)
+
+    return base, bits, char
+
+
+def _add_types():
+    for name, info in _concrete_typeinfo.items():
+        # define C-name and insert typenum and typechar references also
+        allTypes[name] = info.type
+        sctypeDict[name] = info.type
+        sctypeDict[info.char] = info.type
+        sctypeDict[info.num] = info.type
+
+    for name, cls in _abstract_types.items():
+        allTypes[name] = cls
+
+
+_add_types()
+
+# This is the priority order used to assign the bit-sized NPY_INTxx names, 
+# which must match the order in npy_common.h in order for NPY_INTxx 
+# and np.intxx to be consistent. If two C types have the same size, 
+# then the earliest one in this list is used as the sized name.
+_int_ctypes = ['long', 'longlong', 'int', 'short', 'byte']
+_uint_ctypes = list('u' + t for t in _int_ctypes)
+
+def _add_aliases():
+    for name, info in _concrete_typeinfo.items():
+        # these are handled by _add_integer_aliases
+        if name in _int_ctypes or name in _uint_ctypes:
+            continue
+
+        # insert bit-width version for this class (if relevant)
+        base, bit, char = bitname(info.type)
+
+        myname = "%s%d" % (base, bit)
+
+        # ensure that (c)longdouble does not overwrite the aliases assigned to
+        # (c)double
+        if name in ('longdouble', 'clongdouble') and myname in allTypes:
+            continue
+
+        # Add to the main namespace if desired:
+        if bit != 0 and base != "bool":
+            allTypes[myname] = info.type
+
+        # add forward, reverse, and string mapping to numarray
+        sctypeDict[char] = info.type
+
+        # add mapping for both the bit name
+        sctypeDict[myname] = info.type
+
+
+_add_aliases()
+
+def _add_integer_aliases():
+    seen_bits = set()
+    for i_ctype, u_ctype in zip(_int_ctypes, _uint_ctypes):
+        i_info = _concrete_typeinfo[i_ctype]
+        u_info = _concrete_typeinfo[u_ctype]
+        bits = i_info.bits  # same for both
+
+        for info, charname, intname in [
+                (i_info, 'i%d' % (bits//8,), 'int%d' % bits),
+                (u_info, 'u%d' % (bits//8,), 'uint%d' % bits)]:
+            if bits not in seen_bits:
+                # sometimes two different types have the same number of bits
+                # if so, the one iterated over first takes precedence
+                allTypes[intname] = info.type
+                sctypeDict[intname] = info.type
+                sctypeDict[charname] = info.type
+
+        seen_bits.add(bits)
+
+
+_add_integer_aliases()
+
+# We use these later
+void = allTypes['void']
+
+#
+# Rework the Python names (so that float and complex and int are consistent
+#                            with Python usage)
+#
+def _set_up_aliases():
+    type_pairs = [('single', 'float'),
+                  ('csingle', 'cfloat'),
+                  ('intc', 'int'),
+                  ('uintc', 'uint'),
+                  ('int_', 'long'),
+                  ('uint', 'ulong'),
+                  ('bool_', 'bool'),
+                  ('bytes_', 'string'),
+                  ('str_', 'unicode'),
+                  ('object_', 'object'),
+                  ('cfloat', 'cdouble')]
+    for alias, t in type_pairs:
+        allTypes[alias] = allTypes[t]
+        sctypeDict[alias] = sctypeDict[t]
+    # Remove aliases overriding python types and modules
+    to_remove = ['object', 'int', 'float', 'complex', 'bool', 
+                 'string', 'datetime', 'timedelta', 'bytes', 'str']
+
+    for t in to_remove:
+        try:
+            del allTypes[t]
+            del sctypeDict[t]
+        except KeyError:
+            pass
+
+    # Additional aliases in sctypeDict that should not be exposed as attributes
+    attrs_to_remove = ['ulong', 'long', 'unicode', 'cfloat']
+
+    for t in attrs_to_remove:
+        try:
+            del allTypes[t]
+        except KeyError:
+            pass
+
+
+_set_up_aliases()
+
+
+sctypes = {'int': [],
+           'uint': [],
+           'float': [],
+           'complex': [],
+           'others': [bool, object, bytes, str, void]}
+
+
+def _add_array_type(typename, bits):
+    try:
+        t = allTypes['%s%d' % (typename, bits)]
+    except KeyError:
+        pass
+    else:
+        sctypes[typename].append(t)
+
+def _set_array_types():
+    ibytes = [1, 2, 4, 8, 16, 32, 64]
+    fbytes = [2, 4, 8, 10, 12, 16, 32, 64]
+    for bytes in ibytes:
+        bits = 8*bytes
+        _add_array_type('int', bits)
+        _add_array_type('uint', bits)
+    for bytes in fbytes:
+        bits = 8*bytes
+        _add_array_type('float', bits)
+        _add_array_type('complex', 2*bits)
+    _gi = dtype('p')
+    if _gi.type not in sctypes['int']:
+        indx = 0
+        sz = _gi.itemsize
+        _lst = sctypes['int']
+        while (indx < len(_lst) and sz >= _lst[indx](0).itemsize):
+            indx += 1
+        sctypes['int'].insert(indx, _gi.type)
+        sctypes['uint'].insert(indx, dtype('P').type)
+
+
+_set_array_types()
+
+
+# Add additional strings to the sctypeDict
+_toadd = ['int', ('float', 'double'), ('complex', 'cdouble'), 
+          'bool', 'object',
+          'str', 'bytes', ('a', 'bytes_'),
+          ('int0', 'intp'), ('uint0', 'uintp')]
+
+for name in _toadd:
+    if isinstance(name, tuple):
+        sctypeDict[name[0]] = allTypes[name[1]]
+    else:
+        sctypeDict[name] = allTypes['%s_' % name]
+
+del _toadd, name