From d58dce0135e11174cd11df2346bb090ba894e389 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jure=20=C5=A0orn?= Date: Tue, 11 Feb 2020 03:43:11 +0100 Subject: [PATCH] Coroutine section now covers asyncio instead of generator based coroutines --- README.md | 106 +++++++++++++++++++++++++++++++--------------------- index.html | 108 ++++++++++++++++++++++++++++++++--------------------- parse.js | 2 +- 3 files changed, 129 insertions(+), 87 deletions(-) diff --git a/README.md b/README.md index f0f8269..32e4f3d 100644 --- a/README.md +++ b/README.md @@ -13,7 +13,7 @@ Contents **   ** **3. Syntax:** **         ** **[`Args`](#arguments)**__,__ **[`Inline`](#inline)**__,__ **[`Closure`](#closure)**__,__ **[`Decorator`](#decorator)**__,__ **[`Class`](#class)**__,__ **[`Duck_Types`](#duck-types)**__,__ **[`Enum`](#enum)**__,__ **[`Exceptions`](#exceptions)**__.__ **   ** **4. System:** **        ** **[`Print`](#print)**__,__ **[`Input`](#input)**__,__ **[`Command_Line_Arguments`](#command-line-arguments)**__,__ **[`Open`](#open)**__,__ **[`Path`](#path)**__,__ **[`Command_Execution`](#oscommands)**__.__ **   ** **5. Data:** **             ** **[`JSON`](#json)**__,__ **[`Pickle`](#pickle)**__,__ **[`CSV`](#csv)**__,__ **[`SQLite`](#sqlite)**__,__ **[`Bytes`](#bytes)**__,__ **[`Struct`](#struct)**__,__ **[`Array`](#array)**__,__ **[`MemoryView`](#memory-view)**__,__ **[`Deque`](#deque)**__.__ -**   ** **6. Advanced:** **   ** **[`Threading`](#threading)**__,__ **[`Operator`](#operator)**__,__ **[`Introspection`](#introspection)**__,__ **[`Metaprograming`](#metaprograming)**__,__ **[`Eval`](#eval)**__,__ **[`Coroutine`](#coroutine)**__.__ +**   ** **6. Advanced:** **   ** **[`Threading`](#threading)**__,__ **[`Operator`](#operator)**__,__ **[`Introspection`](#introspection)**__,__ **[`Metaprograming`](#metaprograming)**__,__ **[`Eval`](#eval)**__,__ **[`Coroutine`](#coroutines)**__.__ **   ** **7. Libraries:** **      ** **[`Progress_Bar`](#progress-bar)**__,__ **[`Plot`](#plot)**__,__ **[`Table`](#table)**__,__ **[`Curses`](#curses)**__,__ **[`Logging`](#logging)**__,__ **[`Scraping`](#scraping)**__,__ **[`Web`](#web)**__,__ **[`Profile`](#profiling)**__,__ **                                 ** **[`NumPy`](#numpy)**__,__ **[`Image`](#image)**__,__ **[`Animation`](#animation)**__,__ **[`Audio`](#audio)**__.__ @@ -1209,10 +1209,15 @@ class MyIterable: ``` ```python ->>> z = MyIterable([1, 2, 3]) ->>> iter(z) - ->>> 1 in z +>>> obj = MyIterable([1, 2, 3]) +>>> itr = iter(obj) +>>> [next(itr), next(itr), next(itr)] +[1, 2, 3] +>>> [el for el in iter(obj)] +[1, 2, 3] +>>> [el for el in obj] +[1, 2, 3] +>>> 1 in obj True ``` @@ -2095,10 +2100,10 @@ from operator import itemgetter, attrgetter, methodcaller ```python import operator as op -elementwise_sum = map(op.add, list_a, list_b) -product_of_elems = functools.reduce(op.mul, ) sorted_by_second = sorted(, key=op.itemgetter(1)) sorted_by_both = sorted(, key=op.itemgetter(1, 0)) +product_of_elems = functools.reduce(op.mul, ) +elementwise_sum = map(op.add, list_a, list_b) LogicOp = enum.Enum('LogicOp', {'AND': op.and_, 'OR' : op.or_}) last_el = op.methodcaller('pop')() ``` @@ -2238,49 +2243,64 @@ ValueError: malformed node or string ``` -Coroutine ---------- -* **Any function that contains a `'(yield)'` expression returns a coroutine.** -* **Coroutines are similar to iterators, but data needs to be pulled out of an iterator by calling `'next()'`, while we push data into the coroutine by calling `'.send()'`.** -* **Coroutines provide more powerful data routing possibilities than iterators.** +Coroutines +---------- +* **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.** +* **Coroutine definition starts with `'async'` and its call with `'await'`.** +* **`'asyncio.run()'` is the main entry point for asynchronous programs.** +* **Fucntions wait(), gather() and as_completed() can be used when multiple coroutines need to be started at the same time.** -### Helper Decorator -* **All coroutines must first be "primed" by calling `'next()'`.** -* **Remembering to call next() is easy to forget.** -* **Solved by wrapping coroutine functions with the following decorator:** +#### Starts a terminal game where you control an asterisk that must avoid numbers: ```python -def coroutine(func): - def out(*args, **kwargs): - cr = func(*args, **kwargs) - next(cr) - return cr - return out -``` +import asyncio, collections, curses, enum, random -### Pipeline Example -```python -def reader(target): - for i in range(10): - target.send(i) - target.close() +P = collections.namedtuple('P', 'x y') # Position +D = enum.Enum('D', 'n e s w') # Direction -@coroutine -def adder(target): +def main(screen): + curses.curs_set(0) # Makes cursor invisible. + screen.nodelay(True) # Makes getch() non-blocking. + asyncio.run(main_coroutine(screen)) # Starts running asyncio code. + +async def main_coroutine(screen): + state = {'*': P(0, 0), **{id_: P(30, 10) for id_ in range(10)}} + moves = asyncio.Queue() + coros = (*(random_controller(id_, moves) for id_ in range(10)), + human_controller(screen, moves), + model(moves, state, *screen.getmaxyx()), + view(state, screen)) + await asyncio.wait(coros, return_when=asyncio.FIRST_COMPLETED) + +async def random_controller(id_, moves): while True: - value = (yield) - target.send(value + 100) - -@coroutine -def printer(): + moves.put_nowait((id_, random.choice(list(D)))) + await asyncio.sleep(random.random() / 2) + +async def human_controller(screen, moves): + while (ch := screen.getch()) != 27: + key_mappings = {259: D.n, 261: D.e, 258: D.s, 260: D.w} + if ch in key_mappings: + moves.put_nowait(('*', key_mappings[ch])) + await asyncio.sleep(0.01) + +async def model(moves, state, height, width): + while state['*'] not in {p for id_, p in state.items() if id_ != '*'}: + id_, d = await moves.get() + p = state[id_] + deltas = {D.n: P(0, -1), D.e: P(1, 0), D.s: P(0, 1), D.w: P(-1, 0)} + new_p = P(*[sum(a) for a in zip(p, deltas[d])]) + if 0 <= new_p.x < width-1 and 0 <= new_p.y < height: + state[id_] = new_p + +async def view(state, screen): while True: - value = (yield) - print(value, end=' ') -``` + screen.clear() + for id_, p in state.items(): + screen.addstr(p.y, p.x, str(id_)) + await asyncio.sleep(0.01) -```python ->>> reader(adder(printer())) -100 101 102 103 104 105 106 107 108 109 +curses.wrapper(main) ```
@@ -2329,7 +2349,7 @@ with open('test.csv', encoding='utf-8', newline='') as file: Curses ------ -#### Clears the terminal, prints a message and waits for an ESC key press: +#### Clears the terminal, prints a message and waits for the ESC key press: ```python from curses import wrapper, curs_set, ascii from curses import KEY_UP, KEY_RIGHT, KEY_DOWN, KEY_LEFT diff --git a/index.html b/index.html index bf6bc94..f0406db 100644 --- a/index.html +++ b/index.html @@ -1147,10 +1147,15 @@ Hello World! -
>>> z = MyIterable([1, 2, 3])
->>> iter(z)
-<generator object MyIterable.__iter__>
->>> 1 in z
+
>>> obj = MyIterable([1, 2, 3])
+>>> itr = iter(obj)
+>>> [next(itr), next(itr), next(itr)]
+[1, 2, 3]
+>>> [el for el in iter(obj)]
+[1, 2, 3]
+>>> [el for el in obj]
+[1, 2, 3]
+>>> 1 in obj
 True
 

 
Collection
    
@@ -1727,14 +1732,14 @@ db = connector.connect(host=<str>, user=<str>, password=<str>,
 
  • '=' - native byte order
    • 
 
  • '<' - little-endian
    • 
 
  • '>' - big-endian (also '!')
    • 
-
Integer types. Use a capital letter for unsigned type. Standard sizes are in brackets:
    
+
Integer types. Use a capital letter for unsigned type. Standard sizes are in brackets:
    
 
  • 'x' - pad byte
    • 
 
  • 'b' - char (1)
    • 
 
  • 'h' - short (2)
    • 
 
  • 'i' - int (4)
    • 
 
  • 'l' - long (4)
    • 
 
  • 'q' - long long (8)
    • 
-
Floating point types:
    
+
Floating point types:
    
 
  • 'f' - float (4)
    • 
 
  • 'd' - double (8)
    • 
 

@@ -1840,10 +1845,10 @@ lock.release()
 
 
 
import operator as op
-elementwise_sum  = map(op.add, list_a, list_b)
-product_of_elems = functools.reduce(op.mul, <collection>)
 sorted_by_second = sorted(<collection>, key=op.itemgetter(1))
 sorted_by_both   = sorted(<collection>, key=op.itemgetter(1, 0))
+product_of_elems = functools.reduce(op.mul, <collection>)
+elementwise_sum  = map(op.add, list_a, list_b)
 LogicOp          = enum.Enum('LogicOp', {'AND': op.and_, 'OR' : op.or_})
 last_el          = op.methodcaller('pop')(<list>)
 

@@ -1941,46 +1946,63 @@ MyMetaClass.__base__ == type         # MyMetaClass is
 ValueError: malformed node or string
-

#Coroutine

    -
  • Any function that contains a '(yield)' expression returns a coroutine.
    • -
  • 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>)'.
    • -
  • Coroutines provide more powerful data routing possibilities than iterators.
    • -

Helper Decorator

    -
  • All coroutines must first be "primed" by calling 'next(<coroutine>)'.
    • -
  • Remembering to call next() is easy to forget.
    • -
  • Solved by wrapping coroutine functions with the following decorator:
    • -
def coroutine(func):
-    def out(*args, **kwargs):
-        cr = func(*args, **kwargs)
-        next(cr)
-        return cr
-    return out
-
+

#Coroutines

    +
  • 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.
    • +
  • Coroutine definition starts with 'async' and its call with 'await'.
    • +
  • 'asyncio.run(<coroutine>)' is the main entry point for asynchronous programs.
    • +
  • Fucntions wait(), gather() and as_completed() can be used when multiple coroutines need to be started at the same time.
    • +

Starts a terminal game where you control an asterisk that must avoid numbers:

import asyncio, collections, curses, enum, random
 
+P = collections.namedtuple('P', 'x y')         # Position
+D = enum.Enum('D', 'n e s w')                  # Direction
 
+def main(screen):
+    curses.curs_set(0)                         # Makes cursor invisible.
+    screen.nodelay(True)                       # Makes getch() non-blocking.
+    asyncio.run(main_coroutine(screen))        # Starts running asyncio code.
+
+async def main_coroutine(screen):
+    state = {'*': P(0, 0), **{id_: P(30, 10) for id_ in range(10)}}
+    moves = asyncio.Queue()
+    coros = (*(random_controller(id_, moves) for id_ in range(10)),
+             human_controller(screen, moves),
+             model(moves, state, *screen.getmaxyx()),
+             view(state, screen))
+    await asyncio.wait(coros, return_when=asyncio.FIRST_COMPLETED)
+
+async def random_controller(id_, moves):
+    while True:
+        moves.put_nowait((id_, random.choice(list(D))))
+        await asyncio.sleep(random.random() / 2)
+
+async def human_controller(screen, moves):
+    while (ch := screen.getch()) != 27:
+        key_mappings = {259: D.n, 261: D.e, 258: D.s, 260: D.w}
+        if ch in key_mappings:
+            moves.put_nowait(('*', key_mappings[ch]))
+        await asyncio.sleep(0.01)  
+
+async def model(moves, state, height, width):
+    while state['*'] not in {p for id_, p in state.items() if id_ != '*'}:
+        id_, d = await moves.get()
+        p      = state[id_]
+        deltas = {D.n: P(0, -1), D.e: P(1, 0), D.s: P(0, 1), D.w: P(-1, 0)}
+        new_p  = P(*[sum(a) for a in zip(p, deltas[d])])
+        if 0 <= new_p.x < width-1 and 0 <= new_p.y < height:
+            state[id_] = new_p
+
+async def view(state, screen):
+    while True:
+        screen.clear()
+        for id_, p in state.items():
+            screen.addstr(p.y, p.x, str(id_))
+        await asyncio.sleep(0.01)  
 
+curses.wrapper(main)
+
-

Pipeline Example

def reader(target):
-    for i in range(10):
-        target.send(i)
-    target.close()
 
-@coroutine
-def adder(target):
-    while True:
-        value = (yield)
-        target.send(value + 100)
 
-@coroutine
-def printer():
-    while True:
-        value = (yield)
-        print(value, end=' ')
-
- -
>>> reader(adder(printer()))
-100 101 102 103 104 105 106 107 108 109
-


Libraries

#Progress Bar

# $ pip3 install tqdm
 from tqdm import tqdm
@@ -2010,7 +2032,7 @@ pyplot.clf()                                   # Clea
-

#Curses

Clears the terminal, prints a message and waits for an ESC key press:

from curses import wrapper, curs_set, ascii
+
#Curses
Clears the terminal, prints a message and waits for the ESC key press:
from curses import wrapper, curs_set, ascii
 from curses import KEY_UP, KEY_RIGHT, KEY_DOWN, KEY_LEFT
 
 def main():
diff --git a/parse.js b/parse.js
index b97a091..0007148 100755
--- a/parse.js
+++ b/parse.js
@@ -193,7 +193,7 @@ function fixPageBreaksFile() {
 function fixPageBreaksStruct() {
   const formatDiv = $('#floatingpointtypes').parent().parent().parent().parent()
   move(formatDiv, 'floatingpointtypes')
-  move(formatDiv, 'integertypesusecapitalletterforunsignedtypestandardsizesareinbrackets')
+  move(formatDiv, 'integertypesuseacapitalletterforunsignedtypestandardsizesareinbrackets')
   move(formatDiv, 'forstandardsizesstartformatstringwith')
 }