mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-10-06 13:49:30 +00:00
9316e7c014
* flake8 --max-line-length=88
* fixup! Format Python code with psf/black push
Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
79 lines
2.1 KiB
Python
79 lines
2.1 KiB
Python
"""https://en.wikipedia.org/wiki/Jaro%E2%80%93Winkler_distance"""
|
||
|
||
|
||
def jaro_winkler(str1: str, str2: str) -> float:
|
||
"""
|
||
Jaro–Winkler distance is a string metric measuring an edit distance between two
|
||
sequences.
|
||
Output value is between 0.0 and 1.0.
|
||
|
||
>>> jaro_winkler("martha", "marhta")
|
||
0.9611111111111111
|
||
>>> jaro_winkler("CRATE", "TRACE")
|
||
0.7333333333333334
|
||
>>> jaro_winkler("test", "dbdbdbdb")
|
||
0.0
|
||
>>> jaro_winkler("test", "test")
|
||
1.0
|
||
>>> jaro_winkler("hello world", "HeLLo W0rlD")
|
||
0.6363636363636364
|
||
>>> jaro_winkler("test", "")
|
||
0.0
|
||
>>> jaro_winkler("hello", "world")
|
||
0.4666666666666666
|
||
>>> jaro_winkler("hell**o", "*world")
|
||
0.4365079365079365
|
||
"""
|
||
|
||
def get_matched_characters(_str1: str, _str2: str) -> str:
|
||
matched = []
|
||
limit = min(len(_str1), len(_str2)) // 2
|
||
for i, l in enumerate(_str1):
|
||
left = int(max(0, i - limit))
|
||
right = int(min(i + limit + 1, len(_str2)))
|
||
if l in _str2[left:right]:
|
||
matched.append(l)
|
||
_str2 = f"{_str2[0:_str2.index(l)]} {_str2[_str2.index(l) + 1:]}"
|
||
|
||
return "".join(matched)
|
||
|
||
# matching characters
|
||
matching_1 = get_matched_characters(str1, str2)
|
||
matching_2 = get_matched_characters(str2, str1)
|
||
match_count = len(matching_1)
|
||
|
||
# transposition
|
||
transpositions = (
|
||
len([(c1, c2) for c1, c2 in zip(matching_1, matching_2) if c1 != c2]) // 2
|
||
)
|
||
|
||
if not match_count:
|
||
jaro = 0.0
|
||
else:
|
||
jaro = (
|
||
1
|
||
/ 3
|
||
* (
|
||
match_count / len(str1)
|
||
+ match_count / len(str2)
|
||
+ (match_count - transpositions) / match_count
|
||
)
|
||
)
|
||
|
||
# common prefix up to 4 characters
|
||
prefix_len = 0
|
||
for c1, c2 in zip(str1[:4], str2[:4]):
|
||
if c1 == c2:
|
||
prefix_len += 1
|
||
else:
|
||
break
|
||
|
||
return jaro + 0.1 * prefix_len * (1 - jaro)
|
||
|
||
|
||
if __name__ == "__main__":
|
||
import doctest
|
||
|
||
doctest.testmod()
|
||
print(jaro_winkler("hello", "world"))
|