The following requirments that weren't mentioned for solving the following Python Code below:

The provided code for alphabet, test_dups, test_miss, and histogram. 

Your implementation of the has_duplicates function. 

A loop that outputs duplicate information for each string in test_dups. 

Your implementation of the missing_letters function. 

A loop that outputs missing letters for each string in test_miss. 

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 function missing_letters should combine the list of missing letters into a string and return that string. 

Write a loop over the strings in list test_miss and call missing_letters with each string. Print a line for each string listing the missing letters. For example, for the string "aaa", the output should be the following. 

aaa is missing letters bcdefghijklmnopqrstuvwxyz 

If the string has all the letters in alphabet, the output should say it uses all the letters. For example, the output for the string alphabet itself would be the following. 

abcdefghijklmnopqrstuvwxyz uses all the letters 

Print a line like one of the above for each of the strings in test_miss.