count unique letters in a word

[sunny_awesome]

Problem description :
Write a function called unique_english_letters that takes the string word as a parameter. The function should return the total number of unique letters in the string. Uppercase and lowercase letters should be counted as different letters.

We’ve given you a list of every uppercase and lower case letter in the English alphabet. It will be helpful to include that list in your function.

I have written the code :

letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
# Write your unique_english_letters function here:
def unique_english_letters (word) :
  counter = 0
  for i in letters :
    if i in word :
      counter += 1
  return counter
      
# Uncomment these function calls to test your function:
print(unique_english_letters("mississippiiiii"))
# should print 4
print(unique_english_letters("Apple"))
# should print 4

But I don't understand the logic. Can anyone explain me the logic in simple terms ?

[buran]

But I don't understand the logic. Can anyone explain me the logic in simple terms ?

how did you write it, without understanding the logic? i.e. each code snippet implements some logic (algorithm) - with or without success

[perfringo]

I am not able to write code which delivers expected results but must be explained to me by someone else. But it just me

For example, I can easily explain following code which accomplishes task at hand. One of the reasons - I wrote it myself.

def unique_english_letters(text): 
    return len(set(range(65, 91)).union(range(97, 123)) & {ord(chr) for chr in text})

There is nothing wrong with asking for help. Just ability to write code which you don't understand is little bit suspicious.

[jefsummers]

letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" #Makes a string of the letters in alphabet to count
# Write your unique_english_letters function here:
def unique_english_letters (word) :
  counter = 0 #initializes counter
  for i in letters : #creates loop to loop through the letters in the alphabet
    if i in word : #If the letter in the alphabet is in the word....
      counter += 1 #then increment the counter
  return counter
       
# Uncomment these function calls to test your function:
print(unique_english_letters("mississippiiiii"))
# should print 4
print(unique_english_letters("Apple"))
# should print 4

I think the confusion is that I would logically have gone through the letters of "word" and tried to count unique letters. This works it the other way around - go through the alphabet and increment if that letter exists in "word".
Also, thumbs up to Perfringo - this is a great place to use sets. If you know your input will not contain letters, spaces, or punctuation it could be even simpler - return len(set(word))

[kotter]

Maybe you understand this code better:

# write function that counts number of unique english letters
def unique_english_letters(word):
    var1 = [y for y in word if y.isalpha()] #list containing only letters of given string
    var2 = list(set(var1))  #no duplicates in list, all elements are now unique
    return len(var2)    #count number of elements = number of unique letters