Dec 01: Help with Final Project

Learning Objectives

After today's class, you should be able to:

• Write a list comprehension that includes an expression and a condition.
• Explore the contents of a relatively complex object stored in a JSON file.
• Read and write data in JSON files using json.load() and json.dump().

Quiz Debrief

• List comprehensions ( Written Portion)

  • See zyBook and Real Python

  • Example 1: Squaring Numbers

    # Before
    squares = []
    for x in range(10):
        squares.append(x**2)
    
    # After
    squares = [x**2 for x in range(10)]
    

  • Example 2: All Caps Words

    text = "JMU is the BEST"
    
    # Before
    caps = []
    for word in text.split():
        if word.isupper():
            caps.append(word)
    
    # After
    caps = [word for word in text.split() if word.isupper()]
    

• Exploring skyscrapers.json ( Coding Portion)

  • Loading the data from the JSON file
    Note: This was done before calling your function.

    import json
    from pprint import pprint
    
    with open("skyscrapers.json") as file:
        data = json.load(file)
    

  • Lists use indexes. Dictionaries use keys.

    >>> data[0]["name"]
    'The Illinois'
    
    >>> data[0]["statistics"]["height"]
    1609.3599853516
    

Hints on PA3

• Exploring the CS catalog

  import json
  from pprint import pprint
  
  with open("cs_catalog.json") as file:
      data = json.load(file)
  
  pprint(data["CS 149"])
  

• Part B: Testing

  • Need to call load_catalog() in most tests of catalog functions

    def test_total_credits():
        catalog = cu.load_catalog("cs_catalog.json")
        assert cu.total_credits([{"CS 149"}], catalog) == (3, 3)
        assert cu.total_credits([{"CS 149", "CALC"}], catalog) == (6, 7)
    

• Part C: Writing

  • See textwrap documentation

  • Notice that wrap() returns a list

    import textwrap
    pprint(textwrap.wrap(data["CS 149"]["description"], 40))
    

  • Use the str.join() method to convert to string

    >>> "\n".join(["Line 1", "Line 2", "Line 3"])
    'Line 1\nLine 2\nLine 3'