input: def editDistance(string1, string2, m, n):
      """ Compute the edit distance between two given strings.
      The edit distance is defined as the minimum number of operations 
      (insertions, deletions, or substitutions) required to transform 
      one string into the other.
      >>> editDistance("kitten", "sitting", len("kitten"), len("sitting"))
      3
      """
      dp = [[0 for x in range(n+1)] for x in range(m+1)] 
    
      for i in range(m+1): 
          dp[i][0] = i 
    
      for j in range(n+1): 
          dp[0][j] = j 
    
      for i in range(1, m+1): 
          for j in range(1, n+1): 
    
              if string1[i-1] == string2[j-1]: 
                  dp[i][j] = dp[i-1][j-1] 
              else: 
                  dp[i][j] = 1 + min(dp[i][j-1],        
                                     dp[i-1][j],        
                                     dp[i-1][j-1])      
    
      return dp[m][n]
output:     dp = [[0 for x in range(n+1)] for x in range(m+1)] 
    
      for i in range(m+1): 
          dp[i][0] = i 
    
      for j in range(n+1): 
          dp[0][j] = j 
    
      for i in range(1, m+1): 
          for j in range(1, n+1): 
    
              if string1[i-1] == string2[j-1]: 
                  dp[i][j] = dp[i-1][j-1] 
              else: 
                  dp[i][j] = 1 + min(dp[i][j-1],        
                                     dp[i-1][j],        
                                     dp[i-1][j-1])      
    
      return dp[m][n]