Python性能分析
python性能分析装饰器，官方文档
- line profile分析
# line profile
import time
from functools import wraps
from line_profiler import LineProfiler
# 查询接口中每行代码执行的时间
def func_line_time(f):
@wraps(f)
def decorator(*args, **kwargs):
func_return = f(*args, **kwargs)
lp = LineProfiler()
lp_wrap = lp(f)
lp_wrap(*args, **kwargs)
lp.print_stats()
return func_return
return decorator
- cprofile分析器
# cprofile
import cProfile
import pstats
import functools
def do_cProfile(do=False, order='tottime'):
def wrapper(func):
@functools.wraps(func)
def profiled_func(*args, **kwargs):
if do:
profile = cProfile.Profile()
profile.enable()
result = func(*args, **kwargs)
profile.disable()
#profile.print_stats()
ps = pstats.Stats(profile).sort_stats(order).strip_dirs()
ps.print_stats()
return result
else:
result = func(*args, **kwargs)
return result
return profiled_func
return wrapper
分析结果的可视化
- 工具安装
# macos
brew install qcachegrind
brew install graphviz
pip install pyprof2calltree
https://docs.python.org/zh-cn/3/library/profile.html
https://www.jianshu.com/p/c9287e56f44d
https://zhuanlan.zhihu.com/p/24495603
性能优化
- 异步IO: 协程
# python3.6
import asyncio
import time
async def async_say(delay, msg):
await asyncio.sleep(delay)
print(msg)
async def main():
loop = asyncio.get_event_loop()
task1 = loop.create_task(async_say(4, 'hello'))
task2 = loop.create_task(async_say(6, 'world'))
print(f"started at {time.strftime('%X')}")
await task1
await task2
print(f"finished at {time.strftime('%X')}")
loop = asyncio.get_event_loop()
loop.run_until_complete(main())
# 或者以下写法
import asyncio
async def async_say(delay, msg):
await asyncio.sleep(delay)
print(msg)
async def main():
loop = asyncio.get_event_loop()
task1 = loop.create_task(async_say(4, 'hello'))
task2 = loop.create_task(async_say(6, 'world'))
print(f"started at {time.strftime('%X')}")
await task1
await task2
print(f"finished at {time.strftime('%X')}")
loop = asyncio.new_event_loop()
asyncio.set_event_loop(loop)
# loop = asyncio.get_event_loop()
loop.run_until_complete(main())
注意区分写法：
# v1串行运行10s
import asyncio
import time
async def async_say(delay, msg):
await asyncio.sleep(delay)
print(msg)
async def main(loop1):
loop = asyncio.get_event_loop()
print(loop1==loop)
print(f"started at {time.strftime('%X')}")
event_list = []
for i in range(5):
task = loop.create_task(async_say(i, i))
await task # 等待task执行完毕，造成串行
print(f"finished at {time.strftime('%X')}")
loop = asyncio.new_event_loop()
asyncio.set_event_loop(loop)
loop = asyncio.get_event_loop()
loop.run_until_complete(main(loop))
# v2并发运行，4s
import asyncio
import time
async def async_say(delay, msg):
await asyncio.sleep(delay)
print(msg)
async def main(loop1):
loop = asyncio.get_event_loop()
print(loop1==loop)
print(f"started at {time.strftime('%X')}")
event_list = []
for i in range(5):
task = loop.create_task(async_say(i, i))
event_list.append(task)
for i in range(5):
res = await event_list[i]
print(f"finished at {time.strftime('%X')}")
loop = asyncio.new_event_loop()
asyncio.set_event_loop(loop)
loop = asyncio.get_event_loop()
loop.run_until_complete(main(loop))
# 注意以下注释
import asyncio
async def nested():
return 42
async def main():
# Schedule nested() to run soon concurrently
# with "main()".
task = asyncio.create_task(nested())
# "task" can now be used to cancel "nested()", or
# can simply be awaited to wait until it is complete:
await task
asyncio.run(main())
https://docs.python.org/zh-cn/3/library/asyncio-task.html
https://cuiqingcai.com/6160.html
性能优化的建议
https://www.jianshu.com/p/2b71b8fd97aa
https://wiki.python.org/moin/PythonSpeed/PerformanceTips
