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Introduction to OOP in Python with Reeborg

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16. More harvesting challenges

Reeborg’s aunt is a fruit farmer. In her fields, many types of fruits can be found. On a given day, only a certain kind of fruit needs to be harvested. Have a look at worlds Harvest 4a, Harvest 4b, Harvest 4c and Harvest 4d. As he enters the field, Reeborg sees the type of fruit that needs to be harvested as his aunt put a sample there. He picks it up and proceed to harvest all fruits of the similar type.


To fully understand this section, one needs to know about Python lists, and, in particular, list indexing which is something I have not covered yet. I need to do this. Also, in the example below, I need to separate out and have something like:

objects = object_here()
selection = objects[0]

# followed by

selection = object_here()[0]

Reeborg uses the function object_here() which return a list containing the names of the objects found at that location; for the Harvest 4 worlds, the possible objects are "apple, "banana", "orange" or "strawberry" depending if one these objects is found.


There are two new things in the code below which makes is a bit difficult to understand when you read it for the first time. First, we define a new function that takes an argument, in this case fruit. Second, we test to see if two quantities are equal by using two consecutive equal signs: ==.

think(0)  # optional; so it does not take too long...

def harvest_one_row (fruit):
    while front_is_clear():
        if object_here() == fruit:

def go_back_to_beginning_of_row():

def move_to_next_row():

def go_to_first_row():

def complete_one_row():

selection = object_here()[0]   # select the object name from the list
for i in range(6):

Try it!

Complete the above program so that it works in all four worlds: Harvest 4a, Harvest 4b, Harvest 4c and Harvest 4d.