def terms_within(self, fieldname, text, maxdist, prefix=0):
"""Returns a generator of words in the given field within ``maxdist``
Damerau-Levenshtein edit distance of the given text.
Important: the terms are returned in **no particular order**. The only
criterion is that they are within ``maxdist`` edits of ``text``. You
may want to run this method multiple times with increasing ``maxdist``
values to ensure you get the closest matches first. You may also have
additional information (such as term frequency or an acoustic matching
algorithm) you can use to rank terms with the same edit distance.
:param maxdist: the maximum edit distance.
:param prefix: require suggestions to share a prefix of this length
with the given word. This is often justifiable since most
misspellings do not involve the first letter of the word.
Using a prefix dramatically decreases the time it takes to generate
the list of words.
:param seen: an optional set object. Words that appear in the set will
not be yielded.
"""
for word in self.expand_prefix(fieldname, text[:prefix]):
k = distance(word, text, limit=maxdist)
if k <= maxdist:
yield word
def terms_within(self, fieldname, text, maxdist, prefix=0):
"""
Returns a generator of words in the given field within ``maxdist``
Damerau-Levenshtein edit distance of the given text.
Important: the terms are returned in **no particular order**. The only
criterion is that they are within ``maxdist`` edits of ``text``. You
may want to run this method multiple times with increasing ``maxdist``
values to ensure you get the closest matches first. You may also have
additional information (such as term frequency or an acoustic matching
algorithm) you can use to rank terms with the same edit distance.
:param maxdist: the maximum edit distance.
:param prefix: require suggestions to share a prefix of this length
with the given word. This is often justifiable since most
misspellings do not involve the first letter of the word.
Using a prefix dramatically decreases the time it takes to generate
the list of words.
:param seen: an optional set object. Words that appear in the set will
not be yielded.
"""
fieldobj = self.schema[fieldname]
for btext in self.expand_prefix(fieldname, text[:prefix]):
word = fieldobj.from_bytes(btext)
k = distance(word, text, limit=maxdist)
if k <= maxdist:
yield word
def terms_within(self, fieldname, text, maxdist, prefix=0, seen=None):
"""Returns a generator of words in the given field within ``maxdist``
Damerau-Levenshtein edit distance of the given text.
:param maxdist: the maximum edit distance.
:param prefix: require suggestions to share a prefix of this length
with the given word. This is often justifiable since most
misspellings do not involve the first letter of the word.
Using a prefix dramatically decreases the time it takes to generate
the list of words.
:param seen: an optional set object. Words that appear in the set will
not be yielded.
"""
if self.has_word_graph(fieldname):
node = self.word_graph(fieldname)
for word in within(node, text, maxdist, prefix=prefix, seen=seen):
yield word
else:
if seen is None:
seen = set()
for word in self.expand_prefix(fieldname, text[:prefix]):
if word in seen:
continue
if (word == text
or distance(word, text, limit=maxdist) <= maxdist):
yield word
seen.add(word)
def terms_within(self, fieldname, text, maxdist, prefix=0, seen=None):
"""Returns a generator of words in the given field within ``maxdist``
Damerau-Levenshtein edit distance of the given text.
:param maxdist: the maximum edit distance.
:param prefix: require suggestions to share a prefix of this length
with the given word. This is often justifiable since most
misspellings do not involve the first letter of the word.
Using a prefix dramatically decreases the time it takes to generate
the list of words.
:param seen: an optional set object. Words that appear in the set will
not be yielded.
"""
if self.has_word_graph(fieldname):
node = self.word_graph(fieldname)
for word in within(node, text, maxdist, prefix=prefix, seen=seen):
yield word
else:
if seen is None:
seen = set()
for word in self.expand_prefix(fieldname, text[:prefix]):
if word in seen:
continue
k = distance(word, text, limit=maxdist)
if k <= maxdist:
yield word
seen.add(word)
def keyfn(a):
return distance(text, a[0])
def keyfn(a):
return 0 - (1/distance(text, a[0])) * a[1]
def keyfn(a):
return distance(text, a[0])
def keyfn(a):
return 0 - (1 / distance(text, a[0])) * a[1]
