Instructions for oTree workshop participants

To make sure we make the best use of our limited time at the upcoming oTree workshop, please ensure you have adequately prepared by checking the following.

Step 1: Make sure oTree is properly installed

Follow the instructions on Installing oTree to install oTree and PyCharm.

When you run the server, you should be able to go to http://localhost:8000 and see the demo page.

Step 2: Make sure PyCharm is properly installed

In PyCharm, go to public_goods/ The top of the file should look like this:


It should NOT be underlined in red. (this means PyCharm cannot find the correct Python installation):

Step 3: Make sure you understand Python

Follow the Python tutorial here. Once you are done, you should be able to answer the questions in the following quiz (solutions are here).

Question 1

Consider the following dictionary:

v1 = {
    2: 0,
    4: 1,
    1: 3,

What is v1[1]? (You can check your answer by testing it at your Python prompt.)

Question 2

Consider the following list:

v2 = [2, 3, 1]

What is v2[1]? (You can check your answer by testing it at your Python prompt.)

Question 3

Write a function double that doubles a given number.

Question 4

Write a function double_list that takes a list of numbers, and returns a list where each number is double the original. For example: double_list([1,2]) should be [2,4].

Question 5

Consider a list of people like this:

people = [
    {'name': 'Alice', 'gender': 'F', 'age': 15},
    {'name': 'Bob', 'gender': 'M', 'age': 20},
    {'name': 'Claire', 'gender': 'F', 'age': 25},
    {'name': 'David', 'gender': 'M', 'age': 30},
    # etc....

Write a function names() that takes in a list like this and returns just the names of the players. For example names(people) should return:

['Alice', 'Bob', 'Claire', 'David']

Question 6

Using the same structure from above, write a function filter_adult() that returns just the people over 18 years old. For example, if the list just contains the above 4 entries, filter_adult(people) should return:

[{'age': 20, 'gender': 'M', 'name': 'Bob'},
 {'age': 25, 'gender': 'F', 'name': 'Claire'},
 {'age': 30, 'gender': 'M', 'name': 'David'}]

Question 7

Using the same structure from above, Write a function sum_age_by_gender() that adds up the ages of each gender and returns a dictionary with those sums. For example, sum_age_by_gender(people) should return {'M': 50, 'F': 40}.

Information for workshop organizers

Workshops can be of any duration. I suggest at least 2 days. However, oTree is a huge software and I can easily fill 4-5 days of material.

My recommended schedule is usually 10am-5pm or similar, with a lunch break in the middle, and short breaks every hour or so.

The workshops start with a 30-minute slide presentation introducing oTree. Then, I do a brief refresher on Python syntax. Then the rest of the time is spent hands-on programming of oTree games. It’s a combination of instruction and small assignments that participants do either alone or working with the person next to them.