Gentools

Tools for generators, generator functions, and generator-based coroutines.

Key features:

• Create reusable generators
• Compose generators
• Build python 2/3-compatible generators with return.

Installation

pip install gentools

Examples

• Make generator functions reusable:

>>> @reusable
... def countdown(value, step):
...     while value > 0:
...         yield value
...         value -= step

>>> from_3 = countdown(3, step=1)
>>> list(from_3)
[3, 2, 1]
>>> list(from_3)
[3, 2, 1]
>>> isinstance(from_3, countdown)  # generator func is wrapped in a class
True
>>> from_3.step  # attribute access to arguments
1
>>> from_3.replace(value=5)  # create new instance with replaced fields
countdown(value=5, step=1)  # descriptive repr()

• map a generator’s yield, send, and return values:

>>> @map_return('final value: {}'.format)
... @map_send(int)
... @map_yield('the current max is: {}'.format)
... def my_max(value):
...     while value < 100:
...         newvalue = yield value
...         if newvalue > value:
...             value = newvalue
...     return value

>>> gen = my_max(5)
>>> next(gen)
'the current max is: 5'
>>> gen.send(11.3)
'the current max is: 11'
>>> gen.send(104)
StopIteration('final value: 104')

• relay a generator’s yield/send interactions through another generator:

>>> def try_until_positive(outvalue):
...     value = yield outvalue
...     while value < 0:
...         value = yield 'not positive, try again'
...     return value

>>> @relay(try_until_positive)
... def my_max(value):
...     while value < 100:
...         newvalue = yield value
...         if newvalue > value:
...             value = newvalue
...     return value

>>> gen = my_max(5)
>>> next(gen)
5
>>> gen.send(-4)
'not positive, try again'
>>> gen.send(-1)
'not positive, try again'
>>> gen.send(8)
8
>>> gen.send(104)
StopIteration(104)

• make python 2/3 compatible generators with return.

>>> @py2_compatible
... def my_max(value):
...     while value < 100:
...         newvalue = yield value
...         if newvalue > value:
...             value = newvalue
...     return_(value)

Contents:

• API reference
  • Core
  • Types

Release history

development

1.1.0 (2018-03-02)

• added support for python 2.7, 3.3
• new py2_compatible decorator with py2/3 compatible return_
• new stopiter_value helper
• improvements to documentation

1.0.2 (2018-02-08)

• add more examples to docs

1.0.1 (2018-01-27)

• update dev status classifier

1.0.0 (2018-01-27)

• Include compose in public API

0.4.0 (2018-01-24)

• rename pipe to relay.

0.3.1 (2018-01-23)

• fix copy issue in reusable generator .replace()

0.3.0 (2018-01-22)

• make reusable generators callable as methods

0.2.2 (2018-01-21)

• updates to readme

0.2.0 (2018-01-21)

• reorganized modules, improved docs, renamed functions.

0.1.0 (2018-01-17)

• initial release

Indices and tables

• Index
• Module Index
• Search Page