renumbering chapters >= 19
This commit is contained in:
Luciano Ramalho committed
1 parent
cbd13885fc
commit
4ae4096c4c
154 files changed
+7
-1134
No files matched your search
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
@@ -1,4 +0,0 @@
|
||||
Sample code for Chapter 16 - "Coroutines"
|
||||
|
||||
From the book "Fluent Python" by Luciano Ramalho (O'Reilly, 2015)
|
||||
http://shop.oreilly.com/product/0636920032519.do
|
||||
@@ -1,66 +0,0 @@
|
||||
"""
|
||||
Coroutine closing demonstration::
|
||||
|
||||
# tag::DEMO_CORO_EXC_1[]
|
||||
>>> exc_coro = demo_exc_handling()
|
||||
>>> next(exc_coro)
|
||||
-> coroutine started
|
||||
>>> exc_coro.send(11)
|
||||
-> coroutine received: 11
|
||||
>>> exc_coro.send(22)
|
||||
-> coroutine received: 22
|
||||
>>> exc_coro.close()
|
||||
>>> from inspect import getgeneratorstate
|
||||
>>> getgeneratorstate(exc_coro)
|
||||
'GEN_CLOSED'
|
||||
|
||||
# end::DEMO_CORO_EXC_1[]
|
||||
|
||||
Coroutine handling exception::
|
||||
|
||||
# tag::DEMO_CORO_EXC_2[]
|
||||
>>> exc_coro = demo_exc_handling()
|
||||
>>> next(exc_coro)
|
||||
-> coroutine started
|
||||
>>> exc_coro.send(11)
|
||||
-> coroutine received: 11
|
||||
>>> exc_coro.throw(DemoException)
|
||||
*** DemoException handled. Continuing...
|
||||
>>> getgeneratorstate(exc_coro)
|
||||
'GEN_SUSPENDED'
|
||||
|
||||
# end::DEMO_CORO_EXC_2[]
|
||||
|
||||
Coroutine not handling exception::
|
||||
|
||||
# tag::DEMO_CORO_EXC_3[]
|
||||
>>> exc_coro = demo_exc_handling()
|
||||
>>> next(exc_coro)
|
||||
-> coroutine started
|
||||
>>> exc_coro.send(11)
|
||||
-> coroutine received: 11
|
||||
>>> exc_coro.throw(ZeroDivisionError)
|
||||
Traceback (most recent call last):
|
||||
...
|
||||
ZeroDivisionError
|
||||
>>> getgeneratorstate(exc_coro)
|
||||
'GEN_CLOSED'
|
||||
|
||||
# end::DEMO_CORO_EXC_3[]
|
||||
"""
|
||||
|
||||
# tag::EX_CORO_EXC[]
|
||||
class DemoException(Exception):
|
||||
"""An exception type for the demonstration."""
|
||||
|
||||
def demo_exc_handling():
|
||||
print('-> coroutine started')
|
||||
while True:
|
||||
try:
|
||||
x = yield
|
||||
except DemoException: # <1>
|
||||
print('*** DemoException handled. Continuing...')
|
||||
else: # <2>
|
||||
print(f'-> coroutine received: {x!r}')
|
||||
raise RuntimeError('This line should never run.') # <3>
|
||||
# end::EX_CORO_EXC[]
|
||||
@@ -1,61 +0,0 @@
|
||||
"""
|
||||
Second coroutine closing demonstration::
|
||||
|
||||
>>> fin_coro = demo_finally()
|
||||
>>> next(fin_coro)
|
||||
-> coroutine started
|
||||
>>> fin_coro.send(11)
|
||||
-> coroutine received: 11
|
||||
>>> fin_coro.send(22)
|
||||
-> coroutine received: 22
|
||||
>>> fin_coro.close()
|
||||
-> coroutine ending
|
||||
|
||||
|
||||
Second coroutine not handling exception::
|
||||
|
||||
>>> fin_coro = demo_finally()
|
||||
>>> next(fin_coro)
|
||||
-> coroutine started
|
||||
>>> fin_coro.send(11)
|
||||
-> coroutine received: 11
|
||||
>>> fin_coro.throw(ZeroDivisionError) # doctest: +SKIP
|
||||
-> coroutine ending
|
||||
Traceback (most recent call last):
|
||||
File "<stdin>", line 1, in <module>
|
||||
File "coro_exception_demos.py", line 109, in demo_finally
|
||||
print(f'-> coroutine received: {x!r}')
|
||||
ZeroDivisionError
|
||||
|
||||
|
||||
The last test above must be skipped because the output '-> coroutine ending'
|
||||
is not detected by doctest, which raises a false error. However, if you
|
||||
run this file as shown below, you'll see that output "leak" into standard
|
||||
output::
|
||||
|
||||
|
||||
$ python3 -m doctest coro_exception_demo.py
|
||||
-> coroutine ending
|
||||
|
||||
"""
|
||||
|
||||
|
||||
# tag::EX_CORO_FINALLY[]
|
||||
class DemoException(Exception):
|
||||
"""An exception type for the demonstration."""
|
||||
|
||||
|
||||
def demo_finally():
|
||||
print('-> coroutine started')
|
||||
try:
|
||||
while True:
|
||||
try:
|
||||
x = yield
|
||||
except DemoException:
|
||||
print('*** DemoException handled. Continuing...')
|
||||
else:
|
||||
print(f'-> coroutine received: {x!r}')
|
||||
finally:
|
||||
print('-> coroutine ending')
|
||||
|
||||
# end::EX_CORO_FINALLY[]
|
||||
@@ -1,28 +0,0 @@
|
||||
"""
|
||||
A coroutine to compute a running average
|
||||
|
||||
# tag::CORO_AVERAGER_TEST[]
|
||||
>>> coro_avg = averager() # <1>
|
||||
>>> next(coro_avg) # <2>
|
||||
>>> coro_avg.send(10) # <3>
|
||||
10.0
|
||||
>>> coro_avg.send(30)
|
||||
20.0
|
||||
>>> coro_avg.send(5)
|
||||
15.0
|
||||
|
||||
# end::CORO_AVERAGER_TEST[]
|
||||
|
||||
"""
|
||||
|
||||
# tag::CORO_AVERAGER[]
|
||||
def averager():
|
||||
total = 0.0
|
||||
count = 0
|
||||
average = None
|
||||
while True: # <1>
|
||||
term = yield average # <2>
|
||||
total += term
|
||||
count += 1
|
||||
average = total/count
|
||||
# end::CORO_AVERAGER[]
|
||||
@@ -1,30 +0,0 @@
|
||||
# tag::DECORATED_AVERAGER[]
|
||||
"""
|
||||
A coroutine to compute a running average
|
||||
|
||||
>>> coro_avg = averager() # <1>
|
||||
>>> from inspect import getgeneratorstate
|
||||
>>> getgeneratorstate(coro_avg) # <2>
|
||||
'GEN_SUSPENDED'
|
||||
>>> coro_avg.send(10) # <3>
|
||||
10.0
|
||||
>>> coro_avg.send(30)
|
||||
20.0
|
||||
>>> coro_avg.send(5)
|
||||
15.0
|
||||
|
||||
"""
|
||||
|
||||
from coroutil import coroutine # <4>
|
||||
|
||||
@coroutine # <5>
|
||||
def averager(): # <6>
|
||||
total = 0.0
|
||||
count = 0
|
||||
average = None
|
||||
while True:
|
||||
term = yield average
|
||||
total += term
|
||||
count += 1
|
||||
average = total/count
|
||||
# end::DECORATED_AVERAGER[]
|
||||
@@ -1,61 +0,0 @@
|
||||
"""
|
||||
A coroutine to compute a running average.
|
||||
|
||||
Testing ``averager`` by itself::
|
||||
|
||||
# tag::RETURNING_AVERAGER_DEMO1[]
|
||||
|
||||
>>> coro_avg = averager()
|
||||
>>> next(coro_avg)
|
||||
>>> coro_avg.send(10) # <1>
|
||||
>>> coro_avg.send(30)
|
||||
>>> coro_avg.send(6.5)
|
||||
>>> coro_avg.send(None) # <2>
|
||||
Traceback (most recent call last):
|
||||
...
|
||||
StopIteration: Result(count=3, average=15.5)
|
||||
|
||||
# end::RETURNING_AVERAGER_DEMO1[]
|
||||
|
||||
Catching `StopIteration` to extract the value returned by
|
||||
the coroutine::
|
||||
|
||||
# tag::RETURNING_AVERAGER_DEMO2[]
|
||||
|
||||
>>> coro_avg = averager()
|
||||
>>> next(coro_avg)
|
||||
>>> coro_avg.send(10)
|
||||
>>> coro_avg.send(30)
|
||||
>>> coro_avg.send(6.5)
|
||||
>>> try:
|
||||
... coro_avg.send(None)
|
||||
... except StopIteration as exc:
|
||||
... result = exc.value
|
||||
...
|
||||
>>> result
|
||||
Result(count=3, average=15.5)
|
||||
|
||||
# end::RETURNING_AVERAGER_DEMO2[]
|
||||
|
||||
|
||||
"""
|
||||
|
||||
# tag::RETURNING_AVERAGER[]
|
||||
from collections import namedtuple
|
||||
|
||||
Result = namedtuple('Result', 'count average')
|
||||
|
||||
|
||||
def averager():
|
||||
total = 0.0
|
||||
count = 0
|
||||
average = None
|
||||
while True:
|
||||
term = yield
|
||||
if term is None:
|
||||
break # <1>
|
||||
total += term
|
||||
count += 1
|
||||
average = total/count
|
||||
return Result(count, average) # <2>
|
||||
# end::RETURNING_AVERAGER[]
|
||||
@@ -1,107 +0,0 @@
|
||||
"""
|
||||
A coroutine to compute a running average.
|
||||
|
||||
Testing ``averager`` by itself::
|
||||
|
||||
>>> coro_avg = averager()
|
||||
>>> next(coro_avg)
|
||||
>>> coro_avg.send(10)
|
||||
>>> coro_avg.send(30)
|
||||
>>> coro_avg.send(6.5)
|
||||
>>> coro_avg.send(None)
|
||||
Traceback (most recent call last):
|
||||
...
|
||||
StopIteration: Result(count=3, average=15.5)
|
||||
|
||||
|
||||
Driving it with ``yield from``::
|
||||
|
||||
>>> def summarize(results):
|
||||
... while True:
|
||||
... result = yield from averager()
|
||||
... results.append(result)
|
||||
...
|
||||
>>> results = []
|
||||
>>> summary = summarize(results)
|
||||
>>> next(summary)
|
||||
>>> for height in data['girls;m']:
|
||||
... summary.send(height)
|
||||
...
|
||||
>>> summary.send(None)
|
||||
>>> for height in data['boys;m']:
|
||||
... summary.send(height)
|
||||
...
|
||||
>>> summary.send(None)
|
||||
>>> results == [
|
||||
... Result(count=10, average=1.4279999999999997),
|
||||
... Result(count=9, average=1.3888888888888888)
|
||||
... ]
|
||||
True
|
||||
|
||||
"""
|
||||
|
||||
# tag::YIELD_FROM_AVERAGER[]
|
||||
from collections import namedtuple
|
||||
|
||||
Result = namedtuple('Result', 'count average')
|
||||
|
||||
|
||||
# the subgenerator
|
||||
def averager(): # <1>
|
||||
total = 0.0
|
||||
count = 0
|
||||
average = None
|
||||
while True:
|
||||
term = yield # <2>
|
||||
if term is None: # <3>
|
||||
break
|
||||
total += term
|
||||
count += 1
|
||||
average = total/count
|
||||
return Result(count, average) # <4>
|
||||
|
||||
|
||||
# the delegating generator
|
||||
def grouper(results, key): # <5>
|
||||
while True: # <6>
|
||||
results[key] = yield from averager() # <7>
|
||||
|
||||
|
||||
# the client code, a.k.a. the caller
|
||||
def main(data): # <8>
|
||||
results = {}
|
||||
for key, values in data.items():
|
||||
group = grouper(results, key) # <9>
|
||||
next(group) # <10>
|
||||
for value in values:
|
||||
group.send(value) # <11>
|
||||
group.send(None) # important! <12>
|
||||
|
||||
# print(results) # uncomment to debug
|
||||
report(results)
|
||||
|
||||
|
||||
# output report
|
||||
def report(results):
|
||||
for key, result in sorted(results.items()):
|
||||
group, unit = key.split(';')
|
||||
print(f'{result.count:2} {group:5}',
|
||||
f'averaging {result.average:.2f}{unit}')
|
||||
|
||||
|
||||
data = {
|
||||
'girls;kg':
|
||||
[40.9, 38.5, 44.3, 42.2, 45.2, 41.7, 44.5, 38.0, 40.6, 44.5],
|
||||
'girls;m':
|
||||
[1.6, 1.51, 1.4, 1.3, 1.41, 1.39, 1.33, 1.46, 1.45, 1.43],
|
||||
'boys;kg':
|
||||
[39.0, 40.8, 43.2, 40.8, 43.1, 38.6, 41.4, 40.6, 36.3],
|
||||
'boys;m':
|
||||
[1.38, 1.5, 1.32, 1.25, 1.37, 1.48, 1.25, 1.49, 1.46],
|
||||
}
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
main(data)
|
||||
|
||||
# end::YIELD_FROM_AVERAGER[]
|
||||
@@ -1,12 +0,0 @@
|
||||
# tag::CORO_DECO[]
|
||||
from functools import wraps
|
||||
|
||||
def coroutine(func):
|
||||
"""Decorator: primes `func` by advancing to first `yield`"""
|
||||
@wraps(func)
|
||||
def primer(*args, **kwargs): # <1>
|
||||
gen = func(*args, **kwargs) # <2>
|
||||
next(gen) # <3>
|
||||
return gen # <4>
|
||||
return primer
|
||||
# end::CORO_DECO[]
|
||||
@@ -1,203 +0,0 @@
|
||||
|
||||
"""
|
||||
Taxi simulator
|
||||
==============
|
||||
|
||||
Driving a taxi from the console::
|
||||
|
||||
>>> from taxi_sim import taxi_process
|
||||
>>> taxi = taxi_process(ident=13, trips=2, start_time=0)
|
||||
>>> next(taxi)
|
||||
Event(time=0, proc=13, action='leave garage')
|
||||
>>> taxi.send(_.time + 7)
|
||||
Event(time=7, proc=13, action='pick up passenger')
|
||||
>>> taxi.send(_.time + 23)
|
||||
Event(time=30, proc=13, action='drop off passenger')
|
||||
>>> taxi.send(_.time + 5)
|
||||
Event(time=35, proc=13, action='pick up passenger')
|
||||
>>> taxi.send(_.time + 48)
|
||||
Event(time=83, proc=13, action='drop off passenger')
|
||||
>>> taxi.send(_.time + 1)
|
||||
Event(time=84, proc=13, action='going home')
|
||||
>>> taxi.send(_.time + 10)
|
||||
Traceback (most recent call last):
|
||||
File "<stdin>", line 1, in <module>
|
||||
StopIteration
|
||||
|
||||
Sample run with two cars, random seed 10. This is a valid doctest::
|
||||
|
||||
>>> main(num_taxis=2, seed=10)
|
||||
taxi: 0 Event(time=0, proc=0, action='leave garage')
|
||||
taxi: 0 Event(time=5, proc=0, action='pick up passenger')
|
||||
taxi: 1 Event(time=5, proc=1, action='leave garage')
|
||||
taxi: 1 Event(time=10, proc=1, action='pick up passenger')
|
||||
taxi: 1 Event(time=15, proc=1, action='drop off passenger')
|
||||
taxi: 0 Event(time=17, proc=0, action='drop off passenger')
|
||||
taxi: 1 Event(time=24, proc=1, action='pick up passenger')
|
||||
taxi: 0 Event(time=26, proc=0, action='pick up passenger')
|
||||
taxi: 0 Event(time=30, proc=0, action='drop off passenger')
|
||||
taxi: 0 Event(time=34, proc=0, action='going home')
|
||||
taxi: 1 Event(time=46, proc=1, action='drop off passenger')
|
||||
taxi: 1 Event(time=48, proc=1, action='pick up passenger')
|
||||
taxi: 1 Event(time=110, proc=1, action='drop off passenger')
|
||||
taxi: 1 Event(time=139, proc=1, action='pick up passenger')
|
||||
taxi: 1 Event(time=140, proc=1, action='drop off passenger')
|
||||
taxi: 1 Event(time=150, proc=1, action='going home')
|
||||
*** end of events ***
|
||||
|
||||
See longer sample run at the end of this module.
|
||||
|
||||
"""
|
||||
|
||||
import argparse
|
||||
import collections
|
||||
import random
|
||||
import queue
|
||||
|
||||
|
||||
DEFAULT_NUMBER_OF_TAXIS = 3
|
||||
DEFAULT_END_TIME = 180
|
||||
SEARCH_DURATION = 5
|
||||
TRIP_DURATION = 20
|
||||
DEPARTURE_INTERVAL = 5
|
||||
|
||||
Event = collections.namedtuple('Event', 'time proc action')
|
||||
|
||||
|
||||
# tag::TAXI_PROCESS[]
|
||||
def taxi_process(ident, trips, start_time=0): # <1>
|
||||
"""Yield to simulator issuing event at each state change"""
|
||||
time = yield Event(start_time, ident, 'leave garage') # <2>
|
||||
for i in range(trips): # <3>
|
||||
time = yield Event(time, ident, 'pick up passenger') # <4>
|
||||
time = yield Event(time, ident, 'drop off passenger') # <5>
|
||||
|
||||
yield Event(time, ident, 'going home') # <6>
|
||||
# end of taxi process # <7>
|
||||
# end::TAXI_PROCESS[]
|
||||
|
||||
|
||||
# tag::TAXI_SIMULATOR[]
|
||||
class Simulator:
|
||||
|
||||
def __init__(self, procs_map):
|
||||
self.events = queue.PriorityQueue()
|
||||
self.procs = dict(procs_map)
|
||||
|
||||
def run(self, end_time): # <1>
|
||||
"""Schedule and display events until time is up"""
|
||||
# schedule the first event for each cab
|
||||
for _, proc in sorted(self.procs.items()): # <2>
|
||||
first_event = next(proc) # <3>
|
||||
self.events.put(first_event) # <4>
|
||||
|
||||
# main loop of the simulation
|
||||
sim_time = 0 # <5>
|
||||
while sim_time < end_time: # <6>
|
||||
if self.events.empty(): # <7>
|
||||
print('*** end of events ***')
|
||||
break
|
||||
|
||||
current_event = self.events.get() # <8>
|
||||
sim_time, proc_id, previous_action = current_event # <9>
|
||||
print('taxi:', proc_id, proc_id * ' ', current_event) # <10>
|
||||
active_proc = self.procs[proc_id] # <11>
|
||||
next_time = sim_time + compute_duration(previous_action) # <12>
|
||||
try:
|
||||
next_event = active_proc.send(next_time) # <13>
|
||||
except StopIteration:
|
||||
del self.procs[proc_id] # <14>
|
||||
else:
|
||||
self.events.put(next_event) # <15>
|
||||
else: # <16>
|
||||
msg = '*** end of simulation time: {} events pending ***'
|
||||
print(msg.format(self.events.qsize()))
|
||||
# end::TAXI_SIMULATOR[]
|
||||
|
||||
|
||||
def compute_duration(previous_action):
|
||||
"""Compute action duration using exponential distribution"""
|
||||
if previous_action in ['leave garage', 'drop off passenger']:
|
||||
# new state is prowling
|
||||
interval = SEARCH_DURATION
|
||||
elif previous_action == 'pick up passenger':
|
||||
# new state is trip
|
||||
interval = TRIP_DURATION
|
||||
elif previous_action == 'going home':
|
||||
interval = 1
|
||||
else:
|
||||
raise ValueError(f'Unknown previous_action: {previous_action}')
|
||||
return int(random.expovariate(1 / interval)) + 1
|
||||
|
||||
|
||||
def main(end_time=DEFAULT_END_TIME, num_taxis=DEFAULT_NUMBER_OF_TAXIS,
|
||||
seed=None):
|
||||
"""Initialize random generator, build procs and run simulation"""
|
||||
if seed is not None:
|
||||
random.seed(seed) # get reproducible results
|
||||
|
||||
taxis = {i: taxi_process(i, (i + 1) * 2, i * DEPARTURE_INTERVAL)
|
||||
for i in range(num_taxis)}
|
||||
sim = Simulator(taxis)
|
||||
sim.run(end_time)
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
|
||||
parser = argparse.ArgumentParser(
|
||||
description='Taxi fleet simulator.')
|
||||
parser.add_argument('-e', '--end-time', type=int,
|
||||
default=DEFAULT_END_TIME,
|
||||
help='simulation end time; default = %s'
|
||||
% DEFAULT_END_TIME)
|
||||
parser.add_argument('-t', '--taxis', type=int,
|
||||
default=DEFAULT_NUMBER_OF_TAXIS,
|
||||
help='number of taxis running; default = %s'
|
||||
% DEFAULT_NUMBER_OF_TAXIS)
|
||||
parser.add_argument('-s', '--seed', type=int, default=None,
|
||||
help='random generator seed (for testing)')
|
||||
|
||||
args = parser.parse_args()
|
||||
main(args.end_time, args.taxis, args.seed)
|
||||
|
||||
|
||||
"""
|
||||
|
||||
Sample run from the command line, seed=3, maximum elapsed time=120::
|
||||
|
||||
# tag::TAXI_SAMPLE_RUN[]
|
||||
$ python3 taxi_sim.py -s 3 -e 120
|
||||
taxi: 0 Event(time=0, proc=0, action='leave garage')
|
||||
taxi: 0 Event(time=2, proc=0, action='pick up passenger')
|
||||
taxi: 1 Event(time=5, proc=1, action='leave garage')
|
||||
taxi: 1 Event(time=8, proc=1, action='pick up passenger')
|
||||
taxi: 2 Event(time=10, proc=2, action='leave garage')
|
||||
taxi: 2 Event(time=15, proc=2, action='pick up passenger')
|
||||
taxi: 2 Event(time=17, proc=2, action='drop off passenger')
|
||||
taxi: 0 Event(time=18, proc=0, action='drop off passenger')
|
||||
taxi: 2 Event(time=18, proc=2, action='pick up passenger')
|
||||
taxi: 2 Event(time=25, proc=2, action='drop off passenger')
|
||||
taxi: 1 Event(time=27, proc=1, action='drop off passenger')
|
||||
taxi: 2 Event(time=27, proc=2, action='pick up passenger')
|
||||
taxi: 0 Event(time=28, proc=0, action='pick up passenger')
|
||||
taxi: 2 Event(time=40, proc=2, action='drop off passenger')
|
||||
taxi: 2 Event(time=44, proc=2, action='pick up passenger')
|
||||
taxi: 1 Event(time=55, proc=1, action='pick up passenger')
|
||||
taxi: 1 Event(time=59, proc=1, action='drop off passenger')
|
||||
taxi: 0 Event(time=65, proc=0, action='drop off passenger')
|
||||
taxi: 1 Event(time=65, proc=1, action='pick up passenger')
|
||||
taxi: 2 Event(time=65, proc=2, action='drop off passenger')
|
||||
taxi: 2 Event(time=72, proc=2, action='pick up passenger')
|
||||
taxi: 0 Event(time=76, proc=0, action='going home')
|
||||
taxi: 1 Event(time=80, proc=1, action='drop off passenger')
|
||||
taxi: 1 Event(time=88, proc=1, action='pick up passenger')
|
||||
taxi: 2 Event(time=95, proc=2, action='drop off passenger')
|
||||
taxi: 2 Event(time=97, proc=2, action='pick up passenger')
|
||||
taxi: 2 Event(time=98, proc=2, action='drop off passenger')
|
||||
taxi: 1 Event(time=106, proc=1, action='drop off passenger')
|
||||
taxi: 2 Event(time=109, proc=2, action='going home')
|
||||
taxi: 1 Event(time=110, proc=1, action='going home')
|
||||
*** end of events ***
|
||||
# end::TAXI_SAMPLE_RUN[]
|
||||
|
||||
"""
|
||||
@@ -1,255 +0,0 @@
|
||||
|
||||
"""
|
||||
Taxi simulator
|
||||
|
||||
Sample run with two cars, random seed 10. This is a valid doctest.
|
||||
|
||||
>>> main(num_taxis=2, seed=10)
|
||||
taxi: 0 Event(time=0, proc=0, action='leave garage')
|
||||
taxi: 0 Event(time=4, proc=0, action='pick up passenger')
|
||||
taxi: 1 Event(time=5, proc=1, action='leave garage')
|
||||
taxi: 1 Event(time=9, proc=1, action='pick up passenger')
|
||||
taxi: 0 Event(time=10, proc=0, action='drop off passenger')
|
||||
taxi: 1 Event(time=12, proc=1, action='drop off passenger')
|
||||
taxi: 0 Event(time=17, proc=0, action='pick up passenger')
|
||||
taxi: 1 Event(time=19, proc=1, action='pick up passenger')
|
||||
taxi: 1 Event(time=21, proc=1, action='drop off passenger')
|
||||
taxi: 1 Event(time=24, proc=1, action='pick up passenger')
|
||||
taxi: 0 Event(time=28, proc=0, action='drop off passenger')
|
||||
taxi: 1 Event(time=28, proc=1, action='drop off passenger')
|
||||
taxi: 0 Event(time=29, proc=0, action='going home')
|
||||
taxi: 1 Event(time=30, proc=1, action='pick up passenger')
|
||||
taxi: 1 Event(time=61, proc=1, action='drop off passenger')
|
||||
taxi: 1 Event(time=62, proc=1, action='going home')
|
||||
*** end of events ***
|
||||
|
||||
See explanation and longer sample run at the end of this module.
|
||||
|
||||
"""
|
||||
|
||||
import argparse
|
||||
import collections
|
||||
import queue
|
||||
import random
|
||||
|
||||
DEFAULT_NUMBER_OF_TAXIS = 3
|
||||
DEFAULT_END_TIME = 80
|
||||
SEARCH_DURATION = 4
|
||||
TRIP_DURATION = 10
|
||||
DEPARTURE_INTERVAL = 5
|
||||
|
||||
Event = collections.namedtuple('Event', 'time proc action')
|
||||
|
||||
|
||||
def compute_delay(interval):
|
||||
"""Compute action delay using exponential distribution"""
|
||||
return int(random.expovariate(1 / interval)) + 1
|
||||
|
||||
# BEGIN TAXI_PROCESS
|
||||
def taxi_process(ident, trips, start_time=0): # <1>
|
||||
"""Yield to simulator issuing event at each state change"""
|
||||
time = yield Event(start_time, ident, 'leave garage') # <2>
|
||||
for i in range(trips): # <3>
|
||||
prowling_ends = time + compute_delay(SEARCH_DURATION) # <4>
|
||||
time = yield Event(prowling_ends, ident, 'pick up passenger') # <5>
|
||||
|
||||
trip_ends = time + compute_delay(TRIP_DURATION) # <6>
|
||||
time = yield Event(trip_ends, ident, 'drop off passenger') # <7>
|
||||
|
||||
yield Event(time + 1, ident, 'going home') # <8>
|
||||
# end of taxi process # <9>
|
||||
# END TAXI_PROCESS
|
||||
|
||||
# BEGIN TAXI_SIMULATOR
|
||||
class Simulator:
|
||||
|
||||
def __init__(self, procs_map):
|
||||
self.events = queue.PriorityQueue()
|
||||
self.procs = dict(procs_map)
|
||||
|
||||
def run(self, end_time): # <1>
|
||||
"""Schedule and display events until time is up"""
|
||||
# schedule the first event for each cab
|
||||
for _, proc in sorted(self.procs.items()): # <2>
|
||||
first_event = next(proc) # <3>
|
||||
self.events.put(first_event) # <4>
|
||||
|
||||
# main loop of the simulation
|
||||
time = 0
|
||||
while time < end_time: # <5>
|
||||
if self.events.empty(): # <6>
|
||||
print('*** end of events ***')
|
||||
break
|
||||
|
||||
# get and display current event
|
||||
current_event = self.events.get() # <7>
|
||||
print('taxi:', current_event.proc, # <8>
|
||||
current_event.proc * ' ', current_event)
|
||||
|
||||
# schedule next action for current proc
|
||||
time = current_event.time # <9>
|
||||
proc = self.procs[current_event.proc] # <10>
|
||||
try:
|
||||
next_event = proc.send(time) # <11>
|
||||
except StopIteration:
|
||||
del self.procs[current_event.proc] # <12>
|
||||
else:
|
||||
self.events.put(next_event) # <13>
|
||||
else: # <14>
|
||||
msg = '*** end of simulation time: {} events pending ***'
|
||||
print(msg.format(self.events.qsize()))
|
||||
# END TAXI_SIMULATOR
|
||||
|
||||
def main(end_time=DEFAULT_END_TIME, num_taxis=DEFAULT_NUMBER_OF_TAXIS,
|
||||
seed=None):
|
||||
"""Initialize random generator, build procs and run simulation"""
|
||||
if seed is not None:
|
||||
random.seed(seed) # get reproducible results
|
||||
|
||||
taxis = {i: taxi_process(i, (i + 1) * 2, i * DEPARTURE_INTERVAL)
|
||||
for i in range(num_taxis)}
|
||||
sim = Simulator(taxis)
|
||||
sim.run(end_time)
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
|
||||
parser = argparse.ArgumentParser(
|
||||
description='Taxi fleet simulator.')
|
||||
parser.add_argument('-e', '--end-time', type=int,
|
||||
default=DEFAULT_END_TIME,
|
||||
help='simulation end time; default = %s'
|
||||
% DEFAULT_END_TIME)
|
||||
parser.add_argument('-t', '--taxis', type=int,
|
||||
default=DEFAULT_NUMBER_OF_TAXIS,
|
||||
help='number of taxis running; default = %s'
|
||||
% DEFAULT_NUMBER_OF_TAXIS)
|
||||
parser.add_argument('-s', '--seed', type=int, default=None,
|
||||
help='random generator seed (for testing)')
|
||||
|
||||
args = parser.parse_args()
|
||||
main(args.end_time, args.taxis, args.seed)
|
||||
|
||||
|
||||
"""
|
||||
Notes for the ``taxi_process`` coroutine::
|
||||
|
||||
<1> `taxi_process` will be called once per taxi, creating a generator
|
||||
object to represent its operations. `ident` is the number of the taxi
|
||||
(eg. 0, 1, 2 in the sample run); `trips` is the number of trips this
|
||||
taxi will make before going home; `start_time` is when the taxi
|
||||
leaves the garage.
|
||||
|
||||
<2> The first `Event` yielded is `'leave garage'`. This suspends the
|
||||
coroutine, and lets the simulation main loop proceed to the next
|
||||
scheduled event. When it's time to reactivate this process, the main
|
||||
loop will `send` the current simulation time, which is assigned to
|
||||
`time`.
|
||||
|
||||
<3> This block will be repeated once for each trip.
|
||||
|
||||
<4> The ending time of the search for a passenger is computed.
|
||||
|
||||
<5> An `Event` signaling passenger pick up is yielded. The coroutine
|
||||
pauses here. When the time comes to reactivate this coroutine,
|
||||
the main loop will again `send` the current time.
|
||||
|
||||
<6> The ending time of the trip is computed, taking into account the
|
||||
current `time`.
|
||||
|
||||
<7> An `Event` signaling passenger drop off is yielded. Coroutine
|
||||
suspended again, waiting for the main loop to send the time of when
|
||||
it's time to continue.
|
||||
|
||||
<8> The `for` loop ends after the given number of trips, and a final
|
||||
`'going home'` event is yielded, to happen 1 minute after the current
|
||||
time. The coroutine will suspend for the last time. When reactivated,
|
||||
it will be sent the time from the simulation main loop, but here I
|
||||
don't assign it to any variable because it will not be useful.
|
||||
|
||||
<9> When the coroutine falls off the end, the coroutine object raises
|
||||
`StopIteration`.
|
||||
|
||||
|
||||
Notes for the ``Simulator.run`` method::
|
||||
|
||||
<1> The simulation `end_time` is the only required argument for `run`.
|
||||
|
||||
<2> Use `sorted` to retrieve the `self.procs` items ordered by the
|
||||
integer key; we don't care about the key, so assign it to `_`.
|
||||
|
||||
<3> `next(proc)` primes each coroutine by advancing it to the first
|
||||
yield, so it's ready to be sent data. An `Event` is yielded.
|
||||
|
||||
<4> Add each event to the `self.events` `PriorityQueue`. The first
|
||||
event for each taxi is `'leave garage'`, as seen in the sample run
|
||||
(ex_taxi_process>>).
|
||||
|
||||
<5> Main loop of the simulation: run until the current `time` equals
|
||||
or exceeds the `end_time`.
|
||||
|
||||
<6> The main loop may also exit if there are no pending events in the
|
||||
queue.
|
||||
|
||||
<7> Get `Event` with the smallest `time` in the queue; this is the
|
||||
`current_event`.
|
||||
|
||||
<8> Display the `Event`, identifying the taxi and adding indentation
|
||||
according to the taxi id.
|
||||
|
||||
<9> Update the simulation time with the time of the `current_event`.
|
||||
|
||||
<10> Retrieve the coroutine for this taxi from the `self.procs`
|
||||
dictionary.
|
||||
|
||||
<11> Send the `time` to the coroutine. The coroutine will yield the
|
||||
`next_event` or raise `StopIteration` it's finished.
|
||||
|
||||
<12> If `StopIteration` was raised, delete the coroutine from the
|
||||
`self.procs` dictionary.
|
||||
|
||||
<13> Otherwise, put the `next_event` in the queue.
|
||||
|
||||
<14> If the loop exits because the simulation time passed, display the
|
||||
number of events pending (which may be zero by coincidence,
|
||||
sometimes).
|
||||
|
||||
|
||||
Sample run from the command line, seed=24, total elapsed time=160::
|
||||
|
||||
# BEGIN TAXI_SAMPLE_RUN
|
||||
$ python3 taxi_sim.py -s 24 -e 160
|
||||
taxi: 0 Event(time=0, proc=0, action='leave garage')
|
||||
taxi: 0 Event(time=5, proc=0, action='pick up passenger')
|
||||
taxi: 1 Event(time=5, proc=1, action='leave garage')
|
||||
taxi: 1 Event(time=6, proc=1, action='pick up passenger')
|
||||
taxi: 2 Event(time=10, proc=2, action='leave garage')
|
||||
taxi: 2 Event(time=11, proc=2, action='pick up passenger')
|
||||
taxi: 2 Event(time=23, proc=2, action='drop off passenger')
|
||||
taxi: 0 Event(time=24, proc=0, action='drop off passenger')
|
||||
taxi: 2 Event(time=24, proc=2, action='pick up passenger')
|
||||
taxi: 2 Event(time=26, proc=2, action='drop off passenger')
|
||||
taxi: 0 Event(time=30, proc=0, action='pick up passenger')
|
||||
taxi: 2 Event(time=31, proc=2, action='pick up passenger')
|
||||
taxi: 0 Event(time=43, proc=0, action='drop off passenger')
|
||||
taxi: 0 Event(time=44, proc=0, action='going home')
|
||||
taxi: 2 Event(time=46, proc=2, action='drop off passenger')
|
||||
taxi: 2 Event(time=49, proc=2, action='pick up passenger')
|
||||
taxi: 1 Event(time=70, proc=1, action='drop off passenger')
|
||||
taxi: 2 Event(time=70, proc=2, action='drop off passenger')
|
||||
taxi: 2 Event(time=71, proc=2, action='pick up passenger')
|
||||
taxi: 2 Event(time=79, proc=2, action='drop off passenger')
|
||||
taxi: 1 Event(time=88, proc=1, action='pick up passenger')
|
||||
taxi: 2 Event(time=92, proc=2, action='pick up passenger')
|
||||
taxi: 2 Event(time=98, proc=2, action='drop off passenger')
|
||||
taxi: 2 Event(time=99, proc=2, action='going home')
|
||||
taxi: 1 Event(time=102, proc=1, action='drop off passenger')
|
||||
taxi: 1 Event(time=104, proc=1, action='pick up passenger')
|
||||
taxi: 1 Event(time=135, proc=1, action='drop off passenger')
|
||||
taxi: 1 Event(time=136, proc=1, action='pick up passenger')
|
||||
taxi: 1 Event(time=151, proc=1, action='drop off passenger')
|
||||
taxi: 1 Event(time=152, proc=1, action='going home')
|
||||
*** end of events ***
|
||||
# END TAXI_SAMPLE_RUN
|
||||
|
||||
"""
|
||||
@@ -1,215 +0,0 @@
|
||||
|
||||
"""
|
||||
Taxi simulator with delay on output
|
||||
===================================
|
||||
|
||||
This is a variation of ``taxi_sim.py`` which adds a ``-d`` comand-line
|
||||
option. When given, that option adds a delay in the main loop, pausing
|
||||
the simulation for .5s for each "minute" of simulation time.
|
||||
|
||||
|
||||
Driving a taxi from the console::
|
||||
|
||||
>>> from taxi_sim import taxi_process
|
||||
>>> taxi = taxi_process(ident=13, trips=2, start_time=0)
|
||||
>>> next(taxi)
|
||||
Event(time=0, proc=13, action='leave garage')
|
||||
>>> taxi.send(_.time + 7)
|
||||
Event(time=7, proc=13, action='pick up passenger')
|
||||
>>> taxi.send(_.time + 23)
|
||||
Event(time=30, proc=13, action='drop off passenger')
|
||||
>>> taxi.send(_.time + 5)
|
||||
Event(time=35, proc=13, action='pick up passenger')
|
||||
>>> taxi.send(_.time + 48)
|
||||
Event(time=83, proc=13, action='drop off passenger')
|
||||
>>> taxi.send(_.time + 1)
|
||||
Event(time=84, proc=13, action='going home')
|
||||
>>> taxi.send(_.time + 10)
|
||||
Traceback (most recent call last):
|
||||
File "<stdin>", line 1, in <module>
|
||||
StopIteration
|
||||
|
||||
Sample run with two cars, random seed 10. This is a valid doctest::
|
||||
|
||||
>>> main(num_taxis=2, seed=10)
|
||||
taxi: 0 Event(time=0, proc=0, action='leave garage')
|
||||
taxi: 0 Event(time=5, proc=0, action='pick up passenger')
|
||||
taxi: 1 Event(time=5, proc=1, action='leave garage')
|
||||
taxi: 1 Event(time=10, proc=1, action='pick up passenger')
|
||||
taxi: 1 Event(time=15, proc=1, action='drop off passenger')
|
||||
taxi: 0 Event(time=17, proc=0, action='drop off passenger')
|
||||
taxi: 1 Event(time=24, proc=1, action='pick up passenger')
|
||||
taxi: 0 Event(time=26, proc=0, action='pick up passenger')
|
||||
taxi: 0 Event(time=30, proc=0, action='drop off passenger')
|
||||
taxi: 0 Event(time=34, proc=0, action='going home')
|
||||
taxi: 1 Event(time=46, proc=1, action='drop off passenger')
|
||||
taxi: 1 Event(time=48, proc=1, action='pick up passenger')
|
||||
taxi: 1 Event(time=110, proc=1, action='drop off passenger')
|
||||
taxi: 1 Event(time=139, proc=1, action='pick up passenger')
|
||||
taxi: 1 Event(time=140, proc=1, action='drop off passenger')
|
||||
taxi: 1 Event(time=150, proc=1, action='going home')
|
||||
*** end of events ***
|
||||
|
||||
See longer sample run at the end of this module.
|
||||
|
||||
"""
|
||||
|
||||
import random
|
||||
import collections
|
||||
import queue
|
||||
import argparse
|
||||
import time
|
||||
|
||||
DEFAULT_NUMBER_OF_TAXIS = 3
|
||||
DEFAULT_END_TIME = 180
|
||||
SEARCH_DURATION = 5
|
||||
TRIP_DURATION = 20
|
||||
DEPARTURE_INTERVAL = 5
|
||||
|
||||
Event = collections.namedtuple('Event', 'time proc action')
|
||||
|
||||
|
||||
# BEGIN TAXI_PROCESS
|
||||
def taxi_process(ident, trips, start_time=0): # <1>
|
||||
"""Yield to simulator issuing event at each state change"""
|
||||
time = yield Event(start_time, ident, 'leave garage') # <2>
|
||||
for i in range(trips): # <3>
|
||||
time = yield Event(time, ident, 'pick up passenger') # <4>
|
||||
time = yield Event(time, ident, 'drop off passenger') # <5>
|
||||
|
||||
yield Event(time, ident, 'going home') # <6>
|
||||
# end of taxi process # <7>
|
||||
# END TAXI_PROCESS
|
||||
|
||||
|
||||
# BEGIN TAXI_SIMULATOR
|
||||
class Simulator:
|
||||
|
||||
def __init__(self, procs_map):
|
||||
self.events = queue.PriorityQueue()
|
||||
self.procs = dict(procs_map)
|
||||
|
||||
def run(self, end_time, delay=False): # <1>
|
||||
"""Schedule and display events until time is up"""
|
||||
# schedule the first event for each cab
|
||||
for _, proc in sorted(self.procs.items()): # <2>
|
||||
first_event = next(proc) # <3>
|
||||
self.events.put(first_event) # <4>
|
||||
|
||||
# main loop of the simulation
|
||||
sim_time = 0 # <5>
|
||||
while sim_time < end_time: # <6>
|
||||
if self.events.empty(): # <7>
|
||||
print('*** end of events ***')
|
||||
break
|
||||
|
||||
# get and display current event
|
||||
current_event = self.events.get() # <8>
|
||||
if delay:
|
||||
time.sleep((current_event.time - sim_time) / 2)
|
||||
# update the simulation time
|
||||
sim_time, proc_id, previous_action = current_event
|
||||
print('taxi:', proc_id, proc_id * ' ', current_event)
|
||||
active_proc = self.procs[proc_id]
|
||||
# schedule next action for current proc
|
||||
next_time = sim_time + compute_duration(previous_action)
|
||||
try:
|
||||
next_event = active_proc.send(next_time) # <12>
|
||||
except StopIteration:
|
||||
del self.procs[proc_id] # <13>
|
||||
else:
|
||||
self.events.put(next_event) # <14>
|
||||
else: # <15>
|
||||
msg = '*** end of simulation time: {} events pending ***'
|
||||
print(msg.format(self.events.qsize()))
|
||||
# END TAXI_SIMULATOR
|
||||
|
||||
|
||||
def compute_duration(previous_action):
|
||||
"""Compute action duration using exponential distribution"""
|
||||
if previous_action in ['leave garage', 'drop off passenger']:
|
||||
# new state is prowling
|
||||
interval = SEARCH_DURATION
|
||||
elif previous_action == 'pick up passenger':
|
||||
# new state is trip
|
||||
interval = TRIP_DURATION
|
||||
elif previous_action == 'going home':
|
||||
interval = 1
|
||||
else:
|
||||
raise ValueError('Unknown previous_action: %s' % previous_action)
|
||||
return int(random.expovariate(1/interval)) + 1
|
||||
|
||||
|
||||
def main(end_time=DEFAULT_END_TIME, num_taxis=DEFAULT_NUMBER_OF_TAXIS,
|
||||
seed=None, delay=False):
|
||||
"""Initialize random generator, build procs and run simulation"""
|
||||
if seed is not None:
|
||||
random.seed(seed) # get reproducible results
|
||||
|
||||
taxis = {i: taxi_process(i, (i+1)*2, i*DEPARTURE_INTERVAL)
|
||||
for i in range(num_taxis)}
|
||||
sim = Simulator(taxis)
|
||||
sim.run(end_time, delay)
|
||||
|
||||
|
||||
if __name__ == '__main__':
|
||||
|
||||
parser = argparse.ArgumentParser(
|
||||
description='Taxi fleet simulator.')
|
||||
parser.add_argument('-e', '--end-time', type=int,
|
||||
default=DEFAULT_END_TIME,
|
||||
help='simulation end time; default = %s'
|
||||
% DEFAULT_END_TIME)
|
||||
parser.add_argument('-t', '--taxis', type=int,
|
||||
default=DEFAULT_NUMBER_OF_TAXIS,
|
||||
help='number of taxis running; default = %s'
|
||||
% DEFAULT_NUMBER_OF_TAXIS)
|
||||
parser.add_argument('-s', '--seed', type=int, default=None,
|
||||
help='random generator seed (for testing)')
|
||||
parser.add_argument('-d', '--delay', action='store_true',
|
||||
help='introduce delay proportional to simulation time')
|
||||
|
||||
args = parser.parse_args()
|
||||
main(args.end_time, args.taxis, args.seed, args.delay)
|
||||
|
||||
|
||||
"""
|
||||
|
||||
Sample run from the command line, seed=3, maximum elapsed time=120::
|
||||
|
||||
# BEGIN TAXI_SAMPLE_RUN
|
||||
$ python3 taxi_sim.py -s 3 -e 120
|
||||
taxi: 0 Event(time=0, proc=0, action='leave garage')
|
||||
taxi: 0 Event(time=2, proc=0, action='pick up passenger')
|
||||
taxi: 1 Event(time=5, proc=1, action='leave garage')
|
||||
taxi: 1 Event(time=8, proc=1, action='pick up passenger')
|
||||
taxi: 2 Event(time=10, proc=2, action='leave garage')
|
||||
taxi: 2 Event(time=15, proc=2, action='pick up passenger')
|
||||
taxi: 2 Event(time=17, proc=2, action='drop off passenger')
|
||||
taxi: 0 Event(time=18, proc=0, action='drop off passenger')
|
||||
taxi: 2 Event(time=18, proc=2, action='pick up passenger')
|
||||
taxi: 2 Event(time=25, proc=2, action='drop off passenger')
|
||||
taxi: 1 Event(time=27, proc=1, action='drop off passenger')
|
||||
taxi: 2 Event(time=27, proc=2, action='pick up passenger')
|
||||
taxi: 0 Event(time=28, proc=0, action='pick up passenger')
|
||||
taxi: 2 Event(time=40, proc=2, action='drop off passenger')
|
||||
taxi: 2 Event(time=44, proc=2, action='pick up passenger')
|
||||
taxi: 1 Event(time=55, proc=1, action='pick up passenger')
|
||||
taxi: 1 Event(time=59, proc=1, action='drop off passenger')
|
||||
taxi: 0 Event(time=65, proc=0, action='drop off passenger')
|
||||
taxi: 1 Event(time=65, proc=1, action='pick up passenger')
|
||||
taxi: 2 Event(time=65, proc=2, action='drop off passenger')
|
||||
taxi: 2 Event(time=72, proc=2, action='pick up passenger')
|
||||
taxi: 0 Event(time=76, proc=0, action='going home')
|
||||
taxi: 1 Event(time=80, proc=1, action='drop off passenger')
|
||||
taxi: 1 Event(time=88, proc=1, action='pick up passenger')
|
||||
taxi: 2 Event(time=95, proc=2, action='drop off passenger')
|
||||
taxi: 2 Event(time=97, proc=2, action='pick up passenger')
|
||||
taxi: 2 Event(time=98, proc=2, action='drop off passenger')
|
||||
taxi: 1 Event(time=106, proc=1, action='drop off passenger')
|
||||
taxi: 2 Event(time=109, proc=2, action='going home')
|
||||
taxi: 1 Event(time=110, proc=1, action='going home')
|
||||
*** end of events ***
|
||||
# END TAXI_SAMPLE_RUN
|
||||
|
||||
"""
|
||||
@@ -1,52 +0,0 @@
|
||||
# Code below is the expansion of the statement:
|
||||
#
|
||||
# RESULT = yield from EXPR
|
||||
#
|
||||
# Copied verbatim from the Formal Semantics section of
|
||||
# PEP 380 -- Syntax for Delegating to a Subgenerator
|
||||
#
|
||||
# https://www.python.org/dev/peps/pep-0380/#formal-semantics
|
||||
|
||||
|
||||
# tag::YIELD_FROM_EXPANSION[]
|
||||
_i = iter(EXPR) # <1>
|
||||
try:
|
||||
_y = next(_i) # <2>
|
||||
except StopIteration as _e:
|
||||
_r = _e.value # <3>
|
||||
else:
|
||||
while 1: # <4>
|
||||
try:
|
||||
_s = yield _y # <5>
|
||||
except GeneratorExit as _e: # <6>
|
||||
try:
|
||||
_m = _i.close
|
||||
except AttributeError:
|
||||
pass
|
||||
else:
|
||||
_m()
|
||||
raise _e
|
||||
except BaseException as _e: # <7>
|
||||
_x = sys.exc_info()
|
||||
try:
|
||||
_m = _i.throw
|
||||
except AttributeError:
|
||||
raise _e
|
||||
else: # <8>
|
||||
try:
|
||||
_y = _m(*_x)
|
||||
except StopIteration as _e:
|
||||
_r = _e.value
|
||||
break
|
||||
else: # <9>
|
||||
try: # <10>
|
||||
if _s is None: # <11>
|
||||
_y = next(_i)
|
||||
else:
|
||||
_y = _i.send(_s)
|
||||
except StopIteration as _e: # <12>
|
||||
_r = _e.value
|
||||
break
|
||||
|
||||
RESULT = _r # <13>
|
||||
# end::YIELD_FROM_EXPANSION[]
|
||||
@@ -1,32 +0,0 @@
|
||||
# Code below is a very simplified expansion of the statement:
|
||||
#
|
||||
# RESULT = yield from EXPR
|
||||
#
|
||||
# This code assumes that the subgenerator will run to completion,
|
||||
# without the client ever calling ``.throw()`` or ``.close()``.
|
||||
# Also, this code makes no distinction between the client
|
||||
# calling ``next(subgen)`` or ``subgen.send(...)``
|
||||
#
|
||||
# The full expansion is in:
|
||||
# PEP 380 -- Syntax for Delegating to a Subgenerator
|
||||
#
|
||||
# https://www.python.org/dev/peps/pep-0380/#formal-semantics
|
||||
|
||||
|
||||
# tag::YIELD_FROM_EXPANSION_SIMPLIFIED[]
|
||||
_i = iter(EXPR) # <1>
|
||||
try:
|
||||
_y = next(_i) # <2>
|
||||
except StopIteration as _e:
|
||||
_r = _e.value # <3>
|
||||
else:
|
||||
while 1: # <4>
|
||||
_s = yield _y # <5>
|
||||
try:
|
||||
_y = _i.send(_s) # <6>
|
||||
except StopIteration as _e: # <7>
|
||||
_r = _e.value
|
||||
break
|
||||
|
||||
RESULT = _r # <8>
|
||||
# end::YIELD_FROM_EXPANSION_SIMPLIFIED[]
|
||||
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
File renamed without changes.
Loaded 100 of 154 files, more files were not shown because too many files have changed in this diff.
Show more
Reference in new issue
Block a user