I'm trying to count all letters in a txt file then display in descending order

Question

As the title says:

So far this is where I\'m at my code does work however I am having trouble displaying the information in order. Currently it just displays the inf

Answer 1

Displaying in descending order needs to be outside your search-loop otherwise they will be displayed as they are encountered.

Sorting in descending order is quite easy using the built-in sorted (you'll need to set the reverse-argument!)

However python is batteries included and there is already a Counter. So it could be as simply as:

from collections import Counter
from operator import itemgetter

def frequencies(filename):
    # Sets are especially optimized for fast lookups so this will be
    # a perfect fit for the invalid characters.
    invalid = set("‘'`,.?!:;-_\n—' '")

    # Using open in a with block makes sure the file is closed afterwards.
    with open(filename, 'r') as infile:  
        # The "char for char ...." is a conditional generator expression
        # that feeds all characters to the counter that are not invalid.
        counter = Counter(char for char in infile.read().lower() if char not in invalid)

    # If you want to display the values:
    for char, charcount in sorted(counter.items(), key=itemgetter(1), reverse=True):
        print(char, charcount)

The Counter already has a most_common method but you want to display all characters and counts so it's not a good fit in this case. However if you only want to know the x most common counts then it would suitable.