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Coroutine section now covers asyncio instead of generator based coroutines
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‎README.md

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@@ -13,7 +13,7 @@ Contents
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**   ** **3. Syntax:** **         ** **[`Args`](#arguments)**__,__ **[`Inline`](#inline)**__,__ **[`Closure`](#closure)**__,__ **[`Decorator`](#decorator)**__,__ **[`Class`](#class)**__,__ **[`Duck_Types`](#duck-types)**__,__ **[`Enum`](#enum)**__,__ **[`Exceptions`](#exceptions)**__.__
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**   ** **4. System:** **        ** **[`Print`](#print)**__,__ **[`Input`](#input)**__,__ **[`Command_Line_Arguments`](#command-line-arguments)**__,__ **[`Open`](#open)**__,__ **[`Path`](#path)**__,__ **[`Command_Execution`](#oscommands)**__.__
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**   ** **5. Data:** **             ** **[`JSON`](#json)**__,__ **[`Pickle`](#pickle)**__,__ **[`CSV`](#csv)**__,__ **[`SQLite`](#sqlite)**__,__ **[`Bytes`](#bytes)**__,__ **[`Struct`](#struct)**__,__ **[`Array`](#array)**__,__ **[`MemoryView`](#memory-view)**__,__ **[`Deque`](#deque)**__.__
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**   ** **6. Advanced:** **   ** **[`Threading`](#threading)**__,__ **[`Operator`](#operator)**__,__ **[`Introspection`](#introspection)**__,__ **[`Metaprograming`](#metaprograming)**__,__ **[`Eval`](#eval)**__,__ **[`Coroutine`](#coroutine)**__.__
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**   ** **6. Advanced:** **   ** **[`Threading`](#threading)**__,__ **[`Operator`](#operator)**__,__ **[`Introspection`](#introspection)**__,__ **[`Metaprograming`](#metaprograming)**__,__ **[`Eval`](#eval)**__,__ **[`Coroutine`](#coroutines)**__.__
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**   ** **7. Libraries:** **      ** **[`Progress_Bar`](#progress-bar)**__,__ **[`Plot`](#plot)**__,__ **[`Table`](#table)**__,__ **[`Curses`](#curses)**__,__ **[`Logging`](#logging)**__,__ **[`Scraping`](#scraping)**__,__ **[`Web`](#web)**__,__ **[`Profile`](#profiling)**__,__
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**                                 ** **[`NumPy`](#numpy)**__,__ **[`Image`](#image)**__,__ **[`Animation`](#animation)**__,__ **[`Audio`](#audio)**__.__
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@@ -1209,10 +1209,15 @@ class MyIterable:
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```
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```python
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>>> z = MyIterable([1, 2, 3])
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>>> iter(z)
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<generator object MyIterable.__iter__>
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>>> 1 in z
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>>> obj = MyIterable([1, 2, 3])
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>>> itr = iter(obj)
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>>> [next(itr), next(itr), next(itr)]
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[1, 2, 3]
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>>> [el for el in iter(obj)]
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[1, 2, 3]
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>>> [el for el in obj]
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[1, 2, 3]
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>>> 1 in obj
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True
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```
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@@ -2095,10 +2100,10 @@ from operator import itemgetter, attrgetter, methodcaller
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```python
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import operator as op
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elementwise_sum = map(op.add, list_a, list_b)
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product_of_elems = functools.reduce(op.mul, <collection>)
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sorted_by_second = sorted(<collection>, key=op.itemgetter(1))
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sorted_by_both = sorted(<collection>, key=op.itemgetter(1, 0))
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product_of_elems = functools.reduce(op.mul, <collection>)
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elementwise_sum = map(op.add, list_a, list_b)
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LogicOp = enum.Enum('LogicOp', {'AND': op.and_, 'OR' : op.or_})
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last_el = op.methodcaller('pop')(<list>)
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```
@@ -2238,49 +2243,64 @@ ValueError: malformed node or string
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```
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Coroutine
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---------
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* **Any function that contains a `'(yield)'` expression returns a coroutine.**
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* **Coroutines are similar to iterators, but data needs to be pulled out of an iterator by calling `'next(<iter>)'`, while we push data into the coroutine by calling `'<coroutine>.send(<el>)'`.**
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* **Coroutines provide more powerful data routing possibilities than iterators.**
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Coroutines
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----------
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* **Coroutines have a lot in common with threads, but unlike threads, they only give up control when they call another coroutine and they don’t use as much memory.**
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* **Coroutine definition starts with `'async'` and its call with `'await'`.**
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* **`'asyncio.run(<coroutine>)'` is the main entry point for asynchronous programs.**
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* **Fucntions wait(), gather() and as_completed() can be used when multiple coroutines need to be started at the same time.**
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### Helper Decorator
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* **All coroutines must first be "primed" by calling `'next(<coroutine>)'`.**
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* **Remembering to call next() is easy to forget.**
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* **Solved by wrapping coroutine functions with the following decorator:**
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#### Starts a terminal game where you control an asterisk that must avoid numbers:
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```python
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def coroutine(func):
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def out(*args, **kwargs):
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cr = func(*args, **kwargs)
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next(cr)
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return cr
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return out
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```
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import asyncio, collections, curses, enum, random
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### Pipeline Example
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```python
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def reader(target):
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for i in range(10):
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target.send(i)
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target.close()
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P = collections.namedtuple('P', 'x y') # Position
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D = enum.Enum('D', 'n e s w') # Direction
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@coroutine
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def adder(target):
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def main(screen):
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curses.curs_set(0) # Makes cursor invisible.
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screen.nodelay(True) # Makes getch() non-blocking.
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asyncio.run(main_coroutine(screen)) # Starts running asyncio code.
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async def main_coroutine(screen):
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state = {'*': P(0, 0), **{id_: P(30, 10) for id_ in range(10)}}
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moves = asyncio.Queue()
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coros = (*(random_controller(id_, moves) for id_ in range(10)),
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human_controller(screen, moves),
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model(moves, state, *screen.getmaxyx()),
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view(state, screen))
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await asyncio.wait(coros, return_when=asyncio.FIRST_COMPLETED)
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async def random_controller(id_, moves):
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while True:
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value = (yield)
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target.send(value + 100)
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@coroutine
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def printer():
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moves.put_nowait((id_, random.choice(list(D))))
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await asyncio.sleep(random.random() / 2)
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async def human_controller(screen, moves):
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while (ch := screen.getch()) != 27:
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key_mappings = {259: D.n, 261: D.e, 258: D.s, 260: D.w}
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if ch in key_mappings:
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moves.put_nowait(('*', key_mappings[ch]))
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await asyncio.sleep(0.01)
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async def model(moves, state, height, width):
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while state['*'] not in {p for id_, p in state.items() if id_ != '*'}:
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id_, d = await moves.get()
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p = state[id_]
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deltas = {D.n: P(0, -1), D.e: P(1, 0), D.s: P(0, 1), D.w: P(-1, 0)}
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new_p = P(*[sum(a) for a in zip(p, deltas[d])])
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if 0 <= new_p.x < width-1 and 0 <= new_p.y < height:
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state[id_] = new_p
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async def view(state, screen):
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while True:
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value = (yield)
2278-
print(value, end=' ')
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```
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screen.clear()
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for id_, p in state.items():
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screen.addstr(p.y, p.x, str(id_))
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await asyncio.sleep(0.01)
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```python
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>>> reader(adder(printer()))
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100 101 102 103 104 105 106 107 108 109
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curses.wrapper(main)
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```
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<br>
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@@ -2329,7 +2349,7 @@ with open('test.csv', encoding='utf-8', newline='') as file:
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Curses
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------
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#### Clears the terminal, prints a message and waits for an ESC key press:
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#### Clears the terminal, prints a message and waits for the ESC key press:
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```python
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from curses import wrapper, curs_set, ascii
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from curses import KEY_UP, KEY_RIGHT, KEY_DOWN, KEY_LEFT

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