I would like to write my own Python function (i.e. without using any other non base Python functions) to compare the characters in two strings in the following way.

• If the letter in position i of string 1 is the same as the letter in position i of string 2 then "Green" is returned

• If the letter in position i of string 1 is the same as the letter in position [i-1] or [i 1] of string 2 then "Blue" is returned

• If the letter in position i of string 1 is not the same as the letters in position [i-1] , i or [i 1] of string 2 then "White" is returned

The final output of the function should be a tuple of the "Green" / "Blue" / "White" output for each letter.

For example, if we call the function letter_comparison and write:

def letter_comparison(string1, string2):
.....

letter_comparison("chain", "chant") would return "Green", "Green", "Green", "White", "Blue".

Any ideas would be appreciated.

CodePudding user response：

In this way, the function still works depending on the length of the words. I have divided it into two functions for convenience.

def Test(word1,word2,pos):
    if word1[pos] == word2[pos]:
        return "Green"
    elif (pos < (len(word1)-2)) and (word1[pos] == word2[pos 1]):
        return "Blue"
    elif (pos>0) and (word1[pos] == word2[pos-1]):
        return "Blue"
    else:
        return "White"

def letter_comparison(test1, test2):
    risultato = []
    if len(test1) < len(test2):
        for count, char in enumerate(test1):
            risultato.append(Test(test1, test2, count))
    else:
        for count, char in enumerate(test2):
            risultato.append(Test(test1, test2, count))
    return risultato

CodePudding user response：

Have you tried using a for loop?

def letter_comparison(string1, string2):
  myList = []

  if len(string1) != len(string2):
    return
  
  for i in range(len(string1)):
    try:
      l2p = string2[i 1]
    except:
      l2p = None
    try:
      l2m = string2[i-1]
    except:
      l2m = None

    if string1[i] == string2[i]:
      myList.append("Green")
    elif string1[i] == l2p or string1[i] == l2m:
      myList.append("Blue")
    else:
      myList.append("White")

  return myList

otherList = letter_comparison("chain", "chant")
print(otherList)

Otherwise, the question was pretty clear and you did a good job.