Lecture 14 – File Formats and Modules

Data 94, Spring 2021

Review: dictionaries

In [1]:
{'name': 'Junior', 
 'age': 11, 
 'color': 'brown'}
Out[1]:
{'name': 'Junior', 'age': 11, 'color': 'brown'}
In [2]:
tracks = {
    'Drake': ['Best I Ever Had', "Marvin's Room", 'One Dance', 'Controlla'],
    'Lady Gaga': ['Just Dance', 'Paparazzi'],
    'DaBaby': ['Rockstar', 'Suge'],
    'Olivia Rodrigo': ["Driver's License"]
}
In [3]:
tracks['Lady Gaga']
Out[3]:
['Just Dance', 'Paparazzi']
In [4]:
tracks['Drake'].append('One Dance')
In [5]:
tracks['Maroon 5'] = ['Wake Up Call', 'Payphone']
In [6]:
tracks
Out[6]:
{'Drake': ['Best I Ever Had',
  "Marvin's Room",
  'One Dance',
  'Controlla',
  'One Dance'],
 'Lady Gaga': ['Just Dance', 'Paparazzi'],
 'DaBaby': ['Rockstar', 'Suge'],
 'Olivia Rodrigo': ["Driver's License"],
 'Maroon 5': ['Wake Up Call', 'Payphone']}

Quick Check 1

In [7]:
tracks = {
    'Drake': ['Best I Ever Had', "Marvin's Room", 'One Dance', 'Controlla'],
    'Lady Gaga': ['Just Dance', 'Paparazzi'],
    'DaBaby': ['Rockstar', 'Suge'],
    'Olivia Rodrigo': ["Driver's License"]
}
In [ ]:

Data formats

In [8]:
grandma_tree = {
    "name": "Grandma",
    "children": [
        {"name": "Dad",
         "children": [
            {"name": "Me"},
            {"name": "Brother"}
             ]
            },
        {"name": "my aunt",
         "children": [
            {"name": "Cousin 1"},
            {"name": "Cousin 2",
             "children": [
                 {"name": "Cousin 2 Jr."}
                 ]
              }
            ]
        }
    ]
}
In [ ]:

Modules

In [9]:
np.pi

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-9-fcf8569aec5c> in <module>
----> 1 np.pi

NameError: name 'np' is not defined
In [10]:
import numpy as np
In [11]:
np.pi
Out[11]:
3.141592653589793
In [12]:
pi

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-12-f84ab820532c> in <module>
----> 1 pi

NameError: name 'pi' is not defined
In [13]:
np.array([1, 2, 3]) + np.array([4, 5, -3])
Out[13]:
array([5, 7, 0])
In [14]:
Table.read_table('data/pups.csv')

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-14-b575ade1b74b> in <module>
----> 1 Table.read_table('data/pups.csv')

NameError: name 'Table' is not defined
In [15]:
from datascience import *
In [16]:
pups = Table.read_table('data/pups.csv')
In [17]:
pups
Out[17]:
name age breed
Junior Smith 11 cockapoo
Rex Rogers 7 labradoodle
Flash Heat 3 labrador
Reese Bo 4 boston terrier
Polo Cash 2 shih tzu
In [18]:
Table.read_table('covid.csv')
Out[18]:
state cases
california 100
texas 120
In [19]:
import json
def read_json(path):
    return json.load(open(path, 'r'))
In [20]:
read_json('data/family.json')
Out[20]:
{'name': 'Grandma',
 'children': [{'name': 'Dad',
   'children': [{'name': 'Me'}, {'name': 'Brother'}]},
  {'name': 'my aunt',
   'children': [{'name': 'Cousin 1'},
    {'name': 'Cousin 2', 'children': [{'name': 'Cousin 2 Jr.'}]}]}]}