Write a function called missing_letters that takes a string parameter and returns a new string with all the letters of the alphabet that are not in the argument string. The letters in the returned string should be in alphabetical order. Your implementation should use a histogram from the histogram function. It should also use the global variable alphabet. It should use this global variable directly, not through an argument or a local copy. It should loop over the letters in alphabet to determine which are missing from the input parameter.

The program illustrates the use of lists and iterations.

Lists are used to hold multiple values in one variable, while iterations are used for repetitive operations

The missing_letter function written in Python, where comments are used to explain each line is as follows:

#This initializes the alphabet

alphabet = "aefghijklrstuvwxyz"

#This defines the missing_letters function

def missing_letters(s):

    #This creates a list of alphabet

   r = list('')

   #This iterates through the string

   for c in s.lower():

       #This iterates through the list

       if c in r:

       # This removes the present letters

           r.remove(c)  

   #This returns the missing letters

   return ''.join(r)

print(missing_letters(alphabet))

Read more about lists and iterations at:

link

A string parameter and returns new string with all the letters of the alphabet that are not in the argument string. The letters in the returned string should be in alphabetical order. The implementation should uses a histogram from the histogram function

Explanation:

The below code is written in python :

alphabet = ""

test_dups = ["zzz","dog","bookkeeper","subdermatoglyphic","subdermatoglyphics"]

test_miss = ["zzz","subdermatoglyphic","the quick brown fox jumps over the lazy dog"]

def histogram(s):

   d = dict()

   for c in s:

       if c not in d:

           d[c] = 1

       else:

           d[c] += 1

   return d

def has_duplicates(s):

   for v in histogram(s).values():

       if v > 1:

           return True

   return False

def test_dups_loop():

   for s in test_dups:

       print(s + ':', has_duplicates(s))

def missing_letters(s):

   r = list('')

   s = s.lower()

   for c in s.lower():

       if c in r:

           r.remove(c)  # the first matching instance

   return ''.join(r)

def test_miss_loop():

   for s in test_miss:

       print(s + ':', missing_letters(s))

def main():

   test_dups_loop()

   test_miss_loop()

if __name__ == '__main__':

   main()