Python Note

Python 中文官方文檔

str

• str.translate(table [,deletechars]) -> string

>>> from string import punctuation
>>> s = 'abc,./123'
>>> s.translate(None , punctuation)
'abc123'
>>> s.translate('a'* , punctuation)
'aaaaaa'
           

• str.startswith(prefix[, start[, end]]) -> bool
• str.endswith(suffix[, start[, end]]) -> bool

>>> s = 'id=asd123'
>>> s.startswith('id=')
True
>>> s.endswith('id=')
False
           

• str.split([sep [,maxsplit]]) -> list of strings

>>> s='1&2&3&4'
>>> s.split('&')
['1', '2', '3', '4']
>>> s.split('&',)
['1', '2&3&4']
>>> s.split('&',)
['1', '2', '3', '4']
>>> s.split('&',)
['1', '2', '3', '4']
           

• str.center(width[, fillchar]) -> string

>>> s = 'asd123'
>>> s.center()
'       asd123       '
>>> str_list = [' '.join(map(str,range(,i+))) for i in range(,)]
>>> str_list
['1', '1 2', '1 2 3', '1 2 3 4']
>>> for s in str_list:
...     print s.center()
... 
                   
                  
                 
                 
           

• str.expandtabs([tabsize]) -> string

>>> s='1\t2\t3'
>>> s.expandtabs() #default 8
'1       2       3'
>>> s.expandtabs()
'1   2   3'
           

• * *

string

• string.punctuation

>>> from string import punctuation
>>> punctuation
'!"#$%&\'()*+,-./:;<=>[email protected][\\]^_`{|}~'
           

operator

>>> import operator as op
           

• op.itemgetter

>>> mylist = [('a',),('c',),('b',)]
>>> sorted(mylist,key=op.itemgetter()) #sort by col2
[('c', ), ('a', ), ('b', )]
>>> sorted(mylist,key=op.itemgetter()) #sort by col1
[('a', ), ('b', ), ('c', )]
           

time

import time
>>> cur_timestamp = time.time()#目前時間戳

>>> cur_time = time.localtime()#目前時間
time.struct_time(tm_year=, tm_mon=, tm_mday=, tm_hour=, tm_min=, tm_sec=, tm_wday=, tm_yday=, tm_isdst=)
>>> str_time = time.ctime()#目前時間（預設str格式）
'Thu Feb 25 14:27:54 2016'
>>> time.strftime("%Y-%m-%d")#目前時間（自定義str格式）
'2016-02-25'
           

字元串 ⟹ 時間 ⟹ 時間戳

import time
str_tm = "2016-02-25 14:30:24"
tm = time.strptime(str_tm,"%Y-%m-%d %H:%M:%S")
tm_stamp = time.mktime(tm)
print 'tm =' , tm
print 'tm_stamp =' , tm_stamp

"""
tm = time.struct_time(tm_year=2016, tm_mon=2, tm_mday=25, tm_hour=14, tm_min=30, tm_sec=24, tm_wday=3, tm_yday=56, tm_isdst=-1)
tm_stamp = 1456381824.0
"""
           

時間戳 ⟹ 時間 ⟹ 字元串

import time
tm_stamp = 
tm = time.gmtime(tm_stamp)
str_tm = time.strftime("%Y-%m-%d %H:%M:%S",tm)
print 'tm =' , tm
print 'str_tm =' , str_tm

"""
tm = time.struct_time(tm_year=2016, tm_mon=2, tm_mday=25, tm_hour=6, tm_min=30, tm_sec=24, tm_wday=3, tm_yday=56, tm_isdst=0)
str_tm = 2016-02-25 06:30:24
"""
           

計時

>>> begin=time.time();time.sleep();time.time()-begin

           

注：在unix like上使用 time.time() 而在windows中使用time.clock()可以得到更高的精度.

圖檔引自：http://blog.csdn.net/five3/article/details/8771612

datetime

• 詳見：http://my.oschina.net/whp/blog/130710

MAXYEAR && MINYEAR

In []: datetime.MAXYEAR
Out[]: 

In []: datetime.MINYEAR
Out[]: 
           

date

In []: datetime.date.today()
Out[]: datetime.date(, , )

In []: datetime.date.today().year#month，day：2,25
Out[]: 

In []: datetime.date.today().weekday()
Out[]: 
           

datetime

In []: datetime.datetime.today()
Out[]: datetime.datetime(, , , , , , )

In []: datetime.datetime.today().year
Out[]: 

In []: datetime.datetime.today().hour
Out[]: 

In []: datetime.datetime.today().timetuple()
Out[]: time.struct_time(tm_year=, tm_mon=, tm_mday=, tm_hour=, tm_min=, tm_sec=, tm_wday=, tm_yday=, tm_isdst=-)

In []: datetime.datetime.strftime(datetime.datetime.today(),"%Y-%m-%d %H:%M:%S")
Out[]: '2016-02-25 18:23:53'

In []: datetime.datetime.strptime('2016-02-25 18:23:53',"%Y-%m-%d %H:%M:%S")
Out[]: datetime.datetime(, , , , , )
           

注：datetime.datetime.strftime(datetime.datetime.today(),”%Y-%m-%d %H:%M:%S”)

== time.strftime(“%Y-%m-%d %H:%M:%S”)

timedelta

random

Python中的random子產品