Initializing the search function is the first step to the main algorithm. The parameter of the function should include the following two pieces of data needed to perform the search:
- the root node of the tree
- the value being searched for
Besides the parameters, the initial function code can take care of the case if the value is not found. To do this, we will write the last line of the function first:
return None. From the implementation of the previous exercise, we know that when the value
None the message
No path found is output.
Within bfs.py, initialize a function called
bfs(). We’ll use this function to implement our search algorithm.
Inside the body of
The search function will require two pieces of data as input, the root node of the tree and the value being searched for.
Add two parameters to the
bfs() function definition:
Now in main.py, import the
bfs() function from bfs.py.
Lastly, replace the
None assigned to
goal_path with a call to
sample_root_node as the first argument and
"Z" as the second argument.
When you run main.py this time, the output should be the same. The difference is that
goal_path is assigned a
None value from the call to