def cost( word ):
    ...
    ...  the function suite (body of the function cost()
    ...      goes here

# Notice how much shorter and easier to understand the 
#                       main program below here is now.
#        cost(original) focuses on WHAT is happening.

#        The details of HOW cost() penny math of the word is
#            obtained are separated out and located in the function suite.

fin = open("dictionary.txt", "r")

fout = open("dollarWords2.txt", "w")

for original in fin:
    if cost(original) == 100:
        fout.write(original)

fin.close()
fout.close()

print("\nThanks and happy homecoming eve!")