Iterables

with iter(object) methods

• str, list, tuple, set, dict, range
• ___iter__(): returns an iterable_
• __next__(): returns next of iterator_

yield

• will return a generate in a function

Generators

• a special type of iterable
• concise way to construct new iterable object (e.g. iter(<dict>)
• use yield instead of return

• gen = (x ** 2 for x in range(100))
  def _make_gen():
      for x in range(100):
          yield x ** 2
  gen = _make_gen()
  
  def squares(n=10):
  for i in range(1, n+1)
  yield i ** 2
  gen = squares(100)
  # gen is a generator object
  for i in gen:
  print(i)
  

Variable Compare and Copy

Functional Programming in Python

Functional Programming is treating function like an object/data, a function has

• data type: form domain to range
• definition
• name/ address

In Python, the Function is a first-calss object. Some related usage:

• Lambda Function
  • lambda: x, ... :
• decoration
• Partial Argument Application (closure)
  • functools.partial(<func_name>,<parameter to fix>(list of dictionary))
• lamda y: f(5,y) -> 5 fixed
• map( <func\lambda>, <container>)
  • apply every function to a container
• filter(<func>,<container>)
• reduce(<func>,<container>) (from functools)

Testing

Unit Tests

Document Tests

Coding Styles

Zen of Python

PEP8 Coding Style Guid for Python

Google Python Coding Style

• reloading module dependencies
  • use import lib module
    • importlib.reload(<lib>)
  • IPython can do dreload
    • deep reload
• keep objects and data alive in if \_name__ == '__main__' _block
  • everything you want to expose by %run
• flat better than nexted
  • longer files, less jumping around files
    • special about python