python 编程，应该养成哪些好的习惯

python 编程，应该养成哪些好的习惯？

https://www.zhihu.com/question/28966220

无缓冲输出

python -u

sys.stdout.flush()

性能分析

python -m cProfile -o prof.txt my_script.py

import pstats

p = pstats.Stats('prof.txt')

p.strip_dirs().sort_stats('time', 'cumulative').print_stats()

#p.strip_dirs().sort_stats('time', 'cumulative').print_callees()

https://docs.python.org/2/library/profile.html

https://github.com/rkern/line_profiler

https://stackoverflow.com/questions/582336/how-can-you-profile-a-script

导入模块路径

import os

print os.__file__

输出异常行数

print >>sys.stderr, sys.exc_info()[-1].tb_lineno, str(e)

查看调用栈

''.join(traceback.format_stack(frame))

空间使用(ref: http://stackoverflow.com/questions/449560/how-do-i-determine-the-size-of-an-object-in-python )

import sys

from numbers import Number

from collections import Set, Mapping, deque

try: # Python 2

zero_depth_bases = (basestring, Number, xrange, bytearray)

iteritems = 'iteritems'

except NameError: # Python 3

zero_depth_bases = (str, bytes, Number, range, bytearray)

iteritems = 'items'

def getsize(obj_0):

"""Recursively iterate to sum size of object & members."""

def inner(obj, _seen_ids = set()):

obj_id = id(obj)

if obj_id in _seen_ids:

return 0

_seen_ids.add(obj_id)

size = sys.getsizeof(obj)

if isinstance(obj, zero_depth_bases):

pass # bypass remaining control flow and return

elif isinstance(obj, (tuple, list, Set, deque)):

size += sum(inner(i) for i in obj)

elif isinstance(obj, Mapping) or hasattr(obj, iteritems):

size += sum(inner(k) + inner(v) for k, v in getattr(obj, iteritems)())

# Check for custom object instances - may subclass above too

if hasattr(obj, '__dict__'):

size += inner(vars(obj))

if hasattr(obj, '__slots__'): # can have __slots__ with __dict__

size += sum(inner(getattr(obj, s)) for s in obj.__slots__ if hasattr(obj, s))

return size

return inner(obj_0)

Immutable object

如果不注意可能出现意外数据变多、变少的情况。可能导致任务执行过久、输出数据偏少或取值雷同。

巴特西

python 编程，应该养成哪些好的习惯

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