I have an assignment to build a program that, based off an input file, reads text and then generates new text. The dictionary should map n string of letters to a list of letters that could follow the string, based off the text in the input file. Thus far, I have 

```
def create_dic():
    n = order_entry.get()
    inputfile = file_entry.get() #name of input file
    lines = open(inputfile,'r').read() #reads input file into string
    model = {} #empty dictionary to build Markov model

```

For every n-character sequence in the input, I have to "look it up in the dictionary to get a list of possible succeeding characters and get the next character." I'm confused about instruction to look up the string in the dictionary when the dictionary is empty to begin with? Won't there be nothing in the dictionary?