new_contents: # Define a procedure, find_element,
  # using index that takes as its
  # inputs a list and a value of any
  # type, and returns the index of
  # the first element in the input
  # list that matches the value.
  
  # If there is no matching element,
  # return -1.
  
  def find_element(xs, target):
      if target in xs:
          return xs.index(target)
      return -1
  
  #print find_element([1,2,3],3)
  #>>> 2
  
  #print find_element(['alpha','beta'],'gamma')
  #>>> -1
  
subject: Create 09.py