Exam 2 Review

Study Topics

This is just a list of topics to help guide your studying. The list is not in order of importance nor should it be considered a complete list of all topics you should know.

• Regular expressions
  • RE syntax
  • re module functions
  • Applications
• Data structures
  • Nesting data structures
  • Markov chains
  • Sets
  • Graphs
• Set operations
• Graph concepts
  • Nodes, edges
  • Directedness
  • Graph picture vs. Python representation

Sample problems

• Define a function string_replace(text, old, new) that returns a new string that is like the given text string, except that each occurrence of the old string is replaced by the new one.

  An an Orwellian example, string_replace("COMP 200 is great! Python is even greater!", "great", "plusgood") should return "COMP 200 is plusgood! Python is even plusgooder!".

  Alas, CodeSkulptor doesn't implement any of the standard Python functions that do such string replacement. Instead, you should implement this in terms of re.split.

  Test your string_replace function using OwlTest

• Write a function called num_nodes, that, given a graph, returns the number of nodes in the graph.

  Test your num_nodes function using OwlTest

• Write a function called num_out_nodes that, given a graph, returns the number of nodes that have an edge leading out of that node.

  Test your num_out_nodes function using OwlTest

• Briefly explain why in Python you cannot make a set of lists.

See also the problems on last year's exam 2.