core_lessonA

Lesson 10 - I am Your Father

Ch2 Inheritance

• Subclass (child)
• Superclass (parent)
  • Subclass inherits from superclass
• First line in subclass constructor super().__init__(args...)\
• Method overriding
  • To add specifics relating to the subclass(es)

Ch4 More Functions

• any([...]) returns True if at least one is True
• all([...]) returns False if at least one is False
• * wildcard number of args
  • fn(*args), args will be a tuple
• ** wildcard number of keyword args
  • fn(**kwargs), kwargs will be a dict
    • Key is the keyword
    • Value is the argument value
• Forcing keyword / positional args
  • fn(a, *, b) forces b to be a keyword arg
  • fn(a, /, b) forces a to be a positional arg

Ch5 Lambda

• Only have one expression, no statements
• Sorting
  • Use tuples to sorting hierarchy

Ch6 Higher Order Functions

• Functions that take functions are arguments

Ch7 More File Handling

• pickle module, serialises and deserialises data into binary files
• Warning
  • Only specific to python
  • Same python version across pickles
  • Don't unpickle files from untrusted sources
• CSV is a plain text file
  • Structures data in a tabular form
  • Default delimiter: ,
    • Other delimiters: \t, :, ;
• Other modules
  • xml.etree.ElemenTree, creating and reading XML files
  • wave and aifc, reading and writing audio files
  • tarfile, reading and writing tar archives
  • zipfile, working with zip archives
  • configparser, creating and parsing configuration files
  • PyYAML, process YAML
  • PyPDF2, PDF toolkit
  • Pillow, image reading and manipulation

Ch8 Unit Testing

• unittest built-in unit testing module
• Create test class extending unittest.TestCase
  • All test functions start with test_
  • main() function runs all tests
  • -v verbose flag allows for more error logs
• Custom assertions
  • .assertEqual()
  • .assertTrue()
  • .assertIsInstance()
  • .assertIn()
  • .assertIsNone()
  • .assertLess()
  • .assertAlmostEqual()
• Testing fixtures
  • Setup instance of object def setUp(self)
  • Teardown after test def tearDown(self)
  • Reusable
• Other testing modules
  • pytest
  • doctest

Ch9 User-defined Exceptions

• Exception is a superclass of all other exceptions
  • Having Exception has the first except clause will forbid any of the other clauses to fire
• Raising custom exceptions
  • class CustomException(Exception)