Explain this segment of code please: Python

# I have a string variable to guess: "secret word"
secret_word = "secret word"

# I have a list of letters which I guess to be inside the variable secret_word
good_guesses = ["a", "b", "c", "d"]

# The for loop iterates over every letter in secret_word
for letter in secret_word: 

# In each iteration, if the letter is within the list, good_guesses
  if letter in good_guesses: 

# Then the for loop prints that letter. 
# end="" part within print() statement makes sure that we do not go the next line but continue printing horizontally
    print(letter, end="") 

# if the letter is not within the list items, good_guesses, it just prints '_'
  else: 
    print('_', end="")

#For loop ends here.
#The below print statement outside the for loop goes to the next line. It looks better on the console when the program/for loop runs.
print("")