Structured Data: Lists and Dictionaries

A list:

schools = ['Columbia University', 'NYU', 'Cooper Union']

A dictionary:

schools = {
    'institution name':'Columbia University', 
    'student poplation':34000, 
    'degree types':['undergrad','grad']
}

both can be single level:
list: [0,1,2,3,4] vs dictionary: {"a":"b", "c":"d", "e":"f"}

single level

or nested:
list: [[1,2],3,[4,5],[6,7,8]] vs nested dictionary: {"a":"b", "c":{"d":"e"}}

nested

dictionary tree example

List Indexing:

schools = ['Columbia University', 'NYU', 'Cooper Union']
print(schools[-1])
print(schools[0:2])

append:

schools = ['Columbia University', 'NYU', 'Cooper Union']
schools.append('City College')
print(schools)

How a list works, and order of operation:

schools = ['Columbia University', 'NYU', 'Cooper Union']
for school in schools:
    print(school) + ' is a school in New York'

Getting to order of operation:

schools = ['Columbia University', 'NYU', 'Cooper Union']
for school in schools:
    # print(school) + ' is a school in New York'
    schoolSentence = school + ' is a school in New York'
    
schoolSentences = []
schoolSentences.append(schoolSentence)
print(schoolSentences)

Why didn’t it work?

schools = ['Columbia University', 'NYU', 'Cooper Union']
# print(schools[2])
schoolSentences = []
for school in schools:
    # print(school) + ' is a school in New York'
    schoolSentence = school + ' is a school in New York'
    schoolSentences.append(schoolSentence)
    
print(schoolSentences)

Dictionary Keys:

schools = {'institution name':'Columbia University', 'student poplation':34000, 'degree types':['undergrad','grad']}
print(schools)
print(schools['institution name'])
# print(schools[0])

Instagram JSON from a User

Where can we find JSON?

Instagram, Reddit, etc

Type the follow url:

and replace the user “columbiagsapp” with a user of your choice. Maybe ‘highlinenyc’?

Type command or ctrl s to save it as a JSON file.

Lets look at this in a more structured way:

Best JSON Pretty Print to Pretty JSON and Print JSON

Lets open it in Processing:

1. To include the data in a new sketch file by selecting in the menu bar, Sketch → Add File. The file should be in the datafolder of your sketch folder.:

import json
with open('columbiagsapp.json') as file:
    data = json.load(file)
print(data["items"])

lets create a variable to reference the items in our “data” dictionary

items = data["items"]

Now lets find a thumbnail:

thumbnailUrl = data["items"][0]['images']['thumbnail']['url']

Now lets load the thumbnail and draw it on the canvas using the thumbnail url:

size(150, 150)
thumbnail = loadImage(thumbnailUrl)
image(thumbnail, 0, 0)

How do we draw all of the images?
Can we loop over all of the images?

import json
with open('columbiagsapp.json') as file:
    data = json.load(file)
items = data["items"]
#put this into a loop
for item in items:
    thumbnailUrl = item["images"]["thumbnail"]["url"]
    print thumbnailUrl
size(150, 150)
thumbnail = loadImage(thumbnailUrl)
image(thumbnail, 0, 0)

the code above looped over every item and printed the thumbnailUrl string, so when we load the image, we only get the last image we loaded in the for loop:

import json
with open('columbiagsapp.json') as file:
    data = json.load(file)
items = data["items"]
xPos = 0
yPos = 0
for item in items:
    thumbnailUrl = item["images"]["thumbnail"]["url"]
    print(thumbnailUrl)
    xPos += 150
    
    thumbnail = loadImage(thumbnailUrl)
    image(thumbnail, xPos, yPos)
size(1500,150)

Usually we would fix this by drawing the first thumbnail before the loop.