RosettaCode JaroDistance created by tapicella - https://repl.it/Hous/36

RosettaCode JaroDistance.py

'''
http://rosettacode.org/wiki/Jaro_distance
d = 0 if no matching characters
otherwise d = (1/3) * (m/len(s1) + m/len(s2) + (m-(transpose/2))/m )

characters match if distance >= (max(len(s1), len(s2))/2)-1
if distance != 0, counts as a transpose
'''

def JaroDistance(s1, s2):
  l1 = len(s1)
  l2 = len(s2)
  chars1 = list(s1)
  chars2 = list(s2)
  dist = (max(l1, l2)//2)-1
  m = 0
  t = 0
  
  #Find matches
  matches1 = []
  matches2 = []
  for i in range(min(l1, l2)+dist): #check only characters in longer string that are in range
    min_index = max(0, i-dist)
    max_index_1 = min(l1, (i+dist+1))
    max_index_2 = min(l2, (i+dist+1))
    
    if i<l1 and chars1[i] in chars2[min_index:max_index_2]:
      matches1.append(chars1[i])
    if i<l2 and chars2[i] in chars1[min_index:max_index_1]:
      matches2.append(chars2[i])

  m = len(matches1)
  
  #Find transposes
  for j in range(m):
    for k in range(m):
      if matches1[j]==matches2[k]:
        matches1[j] = "T1"
        matches2[k] = "T2"
        if j!=k:
          t+=1
        #Symmetric transposes i.e. AB and BA should only count once. Compare to ABC CAB.
        if matches1[k]==matches2[j]: 
          matches1[k] = "T1"
          matches2[j] = "T2"
      
  print("L1: %d, L2: %d, m: %d, t: %d" % (l1, l2, m, t))
  if m==0:
    jdist = 0
  else:
    jdist = (1/3) * ((m/l1)+(m/l2)+((m-t)/m))
  return round(jdist, 5)
   
print("Jaro Distance for %s and %s is %s" % ("DWAYNE", "DUANE", JaroDistance("DWAYNE", "DUANE")))
print("Jaro Distance for %s and %s is %s" % ("MARTHA", "MARHTA", JaroDistance("MARTHA", "MARHTA")))
print("Jaro Distance for %s and %s is %s" % ("DIXON", "DICKSONX", JaroDistance("DIXON", "DICKSONX")))
print("Jaro Distance for %s and %s is %s" % ("JELLYFISH", "SMELLYFISH", JaroDistance("JELLYFISH", "SMELLYFISH")))