generators-python

Exploration of Python generators

Iteration Protocol

Any object that supports iter() i.e.

• implements __iter__() method, or
• supports the sequence protocol i.e.
  • implements __getitem__() method with integer arguments starting at 0.

is said to be "iterable". iter() returns iterator, so:

iterator  = iter(iterable)

For statement

for x in obj:
    # statements

correponds to

_iter = iter(obj)             # get iterator object
while True:
    try:
        x = _iter.__next__()  # get next item
    except StopIteration:     # no more items
        break
    # statements

A common pattern is to implement __next__() and __iter__() returning object itself. This way object is its own iterator.

Generators

generators.ipynb

Coroutines

coroutines.ipynb