text: s1=input("string1: ")
  s2=input("string2: ")
  def edit(s1, s2):
      if len(s1) < len(s2):
          return levenshtein(s2, s1)
  
      # len(s1) >= len(s2)
      if len(s2) == 0:
          return len(s1)
  
      previous_row = range(len(s2) + 1)
      for i, c1 in enumerate(s1):
          current_row = [i + 1]
          for j, c2 in enumerate(s2):
              insertions = previous_row[j + 1] + 1 # j+1 instead of j since previous_row and current_row are one character longer
              deletions = current_row[j] + 1       # than s2
              substitutions = previous_row[j] + (c1 != c2)
              current_row.append(min(insertions, deletions, substitutions))
          previous_row = current_row
      
      return previous_row[-1]
  print edit(s1,s2)
  