# coding: utf8 from __future__ import unicode_literals import numpy from collections import OrderedDict import msgpack import msgpack_numpy msgpack_numpy.patch() cimport numpy as np from thinc.neural.util import get_array_module from thinc.neural._classes.model import Model from .strings cimport StringStore, hash_string from .compat import basestring_, path2str from . import util def unpickle_vectors(keys_and_rows, data): vectors = Vectors(data=data) for key, row in keys_and_rows: vectors.add(key, row=row) cdef class Vectors: """Store, save and load word vectors. Vectors data is kept in the vectors.data attribute, which should be an instance of numpy.ndarray (for CPU vectors) or cupy.ndarray (for GPU vectors). `vectors.key2row` is a dictionary mapping word hashes to rows in the vectors.data table. Multiple keys can be mapped to the same vector, and not all of the rows in the table need to be assigned --- so len(list(vectors.keys())) may be greater or smaller than vectors.shape[0]. """ cdef public object data cdef public object key2row cdef public object _unset def __init__(self, *, shape=None, data=None, keys=None): """Create a new vector store. shape (tuple): Size of the table, as (# entries, # columns) data (numpy.ndarray): The vector data. keys (iterable): A sequence of keys, aligned with the data. RETURNS (Vectors): The newly created object. """ if data is None: if shape is None: shape = (0,0) data = numpy.zeros(shape, dtype='f') self.data = data self.key2row = OrderedDict() if self.data is not None: self._unset = set(range(self.data.shape[0])) else: self._unset = set() if keys is not None: for i, key in enumerate(keys): self.add(key, row=i) @property def shape(self): """Get `(rows, dims)` tuples of number of rows and number of dimensions in the vector table. RETURNS (tuple): A `(rows, dims)` pair. """ return self.data.shape @property def size(self): """RETURNS (int): rows*dims""" return self.data.shape[0] * self.data.shape[1] @property def is_full(self): """RETURNS (bool): `True` if no slots are available for new keys.""" return len(self._unset) == 0 @property def n_keys(self): """RETURNS (int) The number of keys in the table. Note that this is the number of all keys, not just unique vectors.""" return len(self.key2row) def __reduce__(self): keys_and_rows = self.key2row.items() return (unpickle_vectors, (keys_and_rows, self.data)) def __getitem__(self, key): """Get a vector by key. If the key is not found, a KeyError is raised. key (int): The key to get the vector for. RETURNS (ndarray): The vector for the key. """ i = self.key2row[key] if i is None: raise KeyError(key) else: return self.data[i] def __setitem__(self, key, vector): """Set a vector for the given key. key (int): The key to set the vector for. vector (ndarray): The vector to set. """ i = self.key2row[key] self.data[i] = vector if i in self._unset: self._unset.remove(i) def __iter__(self): """Iterate over the keys in the table. YIELDS (int): A key in the table. """ yield from self.key2row def __len__(self): """Return the number of vectors in the table. RETURNS (int): The number of vectors in the data. """ return self.data.shape[0] def __contains__(self, key): """Check whether a key has been mapped to a vector entry in the table. key (int): The key to check. RETURNS (bool): Whether the key has a vector entry. """ return key in self.key2row def resize(self, shape, inplace=False): """Resize the underlying vectors array. If inplace=True, the memory is reallocated. This may cause other references to the data to become invalid, so only use inplace=True if you're sure that's what you want. If the number of vectors is reduced, keys mapped to rows that have been deleted are removed. These removed items are returned as a list of `(key, row)` tuples. """ if inplace: self.data.resize(shape, refcheck=False) else: xp = get_array_module(self.data) self.data = xp.resize(self.data, shape) filled = {row for row in self.key2row.values()} self._unset = {row for row in range(shape[0]) if row not in filled} removed_items = [] for key, row in dict(self.key2row.items()): if row >= shape[0]: self.key2row.pop(key) removed_items.append((key, row)) return removed_items def keys(self): """A sequence of the keys in the table. RETURNS (iterable): The keys. """ return self.key2row.keys() def values(self): """Iterate over vectors that have been assigned to at least one key. Note that some vectors may be unassigned, so the number of vectors returned may be less than the length of the vectors table. YIELDS (ndarray): A vector in the table. """ for row, vector in enumerate(range(self.data.shape[0])): if row not in self._unset: yield vector def items(self): """Iterate over `(key, vector)` pairs. YIELDS (tuple): A key/vector pair. """ for key, row in self.key2row.items(): yield key, self.data[row] def find(self, *, key=None, keys=None, row=None, rows=None): '''Lookup one or more keys by row, or vice versa. key (unicode / int): Find the row that the given key points to. Returns int, -1 if missing. keys (sequence): Find rows that the keys point to. Returns ndarray. row (int): Find the first key that point to the row. Returns int. rows (sequence): Find the first keys that points to the rows. Returns ndarray. ''' if sum(arg is None for arg in (key, keys, row, rows)) != 3: raise ValueError("One (and only one) keyword arg must be set.") xp = get_array_module(self.data) if key is not None: if isinstance(key, basestring_): key = hash_string(key) return self.key2row.get(key, -1) elif keys is not None: keys = [hash_string(key) if isinstance(key, basestring_) else key for key in keys] rows = [self.key2row.get(key, -1.) for key in keys] return xp.asarray(rows, dtype='i') else: targets = set() if row is not None: targets.add(row) else: targets.update(rows) results = [] for key, row in self.key2row.items(): if row in targets: results.append(key) targets.remove(row) return xp.asarray(results, dtype='uint64') def add(self, key, *, vector=None, row=None): """Add a key to the table. Keys can be mapped to an existing vector by setting `row`, or a new vector can be added. key (int): The key to add. vector (ndarray / None): A vector to add for the key. row (int / None): The row number of a vector to map the key to. RETURNS (int): The row the vector was added to. """ if isinstance(key, basestring): key = hash_string(key) if row is None and key in self.key2row: row = self.key2row[key] elif row is None: if self.is_full: raise ValueError("Cannot add new key to vectors -- full") row = min(self._unset) self.key2row[key] = row if vector is not None: self.data[row] = vector if row in self._unset: self._unset.remove(row) return row def most_similar(self, queries, *, batch_size=1024): """For each of the given vectors, find the single entry most similar to it, by cosine. Queries are by vector. Results are returned as a `(keys, best_rows, scores)` tuple. If `queries` is large, the calculations are performed in chunks, to avoid consuming too much memory. You can set the `batch_size` to control the size/space trade-off during the calculations. queries (ndarray): An array with one or more vectors. batch_size (int): The batch size to use. RETURNS (tuple): The most similar entry as a `(keys, best_rows, scores)` tuple. """ xp = get_array_module(self.data) vectors = self.data / xp.linalg.norm(self.data, axis=1, keepdims=True) best_rows = xp.zeros((queries.shape[0],), dtype='i') scores = xp.zeros((queries.shape[0],), dtype='f') # Work in batches, to avoid memory problems. for i in range(0, queries.shape[0], batch_size): batch = queries[i : i+batch_size] batch /= xp.linalg.norm(batch, axis=1, keepdims=True) # batch e.g. (1024, 300) # vectors e.g. (10000, 300) # sims e.g. (1024, 10000) sims = xp.dot(batch, vectors.T) best_rows[i:i+batch_size] = sims.argmax(axis=1) scores[i:i+batch_size] = sims.max(axis=1) keys = self.find(rows=best_rows) return (keys, best_rows, scores) def from_glove(self, path): """Load GloVe vectors from a directory. Assumes binary format, that the vocab is in a vocab.txt, and that vectors are named vectors.{size}.[fd].bin, e.g. vectors.128.f.bin for 128d float32 vectors, vectors.300.d.bin for 300d float64 (double) vectors, etc. By default GloVe outputs 64-bit vectors. path (unicode / Path): The path to load the GloVe vectors from. RETURNS: A `StringStore` object, holding the key-to-string mapping. """ path = util.ensure_path(path) width = None for name in path.iterdir(): if name.parts[-1].startswith('vectors'): _, dims, dtype, _2 = name.parts[-1].split('.') width = int(dims) break else: raise IOError("Expected file named e.g. vectors.128.f.bin") bin_loc = path / 'vectors.{dims}.{dtype}.bin'.format(dims=dims, dtype=dtype) xp = get_array_module(self.data) self.data = None with bin_loc.open('rb') as file_: self.data = xp.fromfile(file_, dtype=dtype) if dtype != 'float32': self.data = xp.ascontiguousarray(self.data, dtype='float32') n = 0 strings = StringStore() with (path / 'vocab.txt').open('r') as file_: for i, line in enumerate(file_): key = strings.add(line.strip()) self.add(key, row=i) return strings def to_disk(self, path, **exclude): """Save the current state to a directory. path (unicode / Path): A path to a directory, which will be created if it doesn't exists. Either a string or a Path-like object. """ xp = get_array_module(self.data) if xp is numpy: save_array = lambda arr, file_: xp.save(file_, arr, allow_pickle=False) else: save_array = lambda arr, file_: xp.save(file_, arr) serializers = OrderedDict(( ('vectors', lambda p: save_array(self.data, p.open('wb'))), ('key2row', lambda p: msgpack.dump(self.key2row, p.open('wb'))) )) return util.to_disk(path, serializers, exclude) def from_disk(self, path, **exclude): """Loads state from a directory. Modifies the object in place and returns it. path (unicode / Path): Directory path, string or Path-like object. RETURNS (Vectors): The modified object. """ def load_key2row(path): if path.exists(): self.key2row = msgpack.load(path.open('rb')) for key, row in self.key2row.items(): if row in self._unset: self._unset.remove(row) def load_keys(path): if path.exists(): keys = numpy.load(str(path)) for i, key in enumerate(keys): self.add(key, row=i) def load_vectors(path): xp = Model.ops.xp if path.exists(): self.data = xp.load(path) serializers = OrderedDict(( ('key2row', load_key2row), ('keys', load_keys), ('vectors', load_vectors), )) util.from_disk(path, serializers, exclude) return self def to_bytes(self, **exclude): """Serialize the current state to a binary string. **exclude: Named attributes to prevent from being serialized. RETURNS (bytes): The serialized form of the `Vectors` object. """ def serialize_weights(): if hasattr(self.data, 'to_bytes'): return self.data.to_bytes() else: return msgpack.dumps(self.data) serializers = OrderedDict(( ('key2row', lambda: msgpack.dumps(self.key2row)), ('vectors', serialize_weights) )) return util.to_bytes(serializers, exclude) def from_bytes(self, data, **exclude): """Load state from a binary string. data (bytes): The data to load from. **exclude: Named attributes to prevent from being loaded. RETURNS (Vectors): The `Vectors` object. """ def deserialize_weights(b): if hasattr(self.data, 'from_bytes'): self.data.from_bytes() else: self.data = msgpack.loads(b) deserializers = OrderedDict(( ('key2row', lambda b: self.key2row.update(msgpack.loads(b))), ('vectors', deserialize_weights) )) util.from_bytes(data, deserializers, exclude) return self