Hangman game, with the number of guesses depending on the word length
dropping you some small comments about the code you posted


The idea of splitting the code into smaller functions works, the first methods you have are 10 lines or less and is not hard to follow what they do. Would be interesting to go ahead and split some parts of hangman() into smaller pieces as well
The name of the variable for your application main loop can be a bit misleading, would suggest something different instead of no_of_guesses, you could think of a can_guess(counter) boolean function that checks a counter and returns if the counter reached zero
Another part that may be tricky to understand is if blank==random_word, could be easier to read if it was more verbose about what happens, like in if not has_more_characters_to_guess(random_word)
As a general advice, don't be shy to have longer function names. available_letters is preferred to any shorter name. fill_blank can be replaced with get_partial_word_guess which may be more legible and explain a bit more on the insights