Hints for getting started on part 1:

Create a new empty dictionary for storing the predator/prey relationships

For every line in the file
  Remove the newline character from the end of the line
  Break the line into pieces, either by using split, or by slicing the string
    - everything before " eats " is the predator
    - everything after " eats " is the prey

  If the predator is already in the dictionary
    Add the prey to the end of the list of organisms eaten by the predator
  Else
    Add the predator to the dictionary as a new key, with a value that is a
      list of one element, containing the prey