. , , , , . ; , . , , . .
Python.
SUFFIXES = {1000: ['KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'],
1024: ['KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB']}
Python.
>>> SUFFIXES = {1000: ['KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'],
... 1024: ['KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB']}
>>> len(SUFFIXES) ①
2
>>> 1000 in SUFFIXES ②
True
>>> SUFFIXES[1000] ③
['KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB']
>>> SUFFIXES[1024] ④
['KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB']
>>> SUFFIXES[1000][3] ⑤
'TB'
① | , , len() . |
② | , , in, , . |
③ | 1000 SUFFIXES; ( , ). |
④ | , 1024 SUFFIXES; . |
⑤ | SUFFIXES[1000] , , . |
, .
, if.
>>> def is_it_true(anything):
... if anything:
... print(", ")
... else:
... print(", ")
...
>>> is_it_true({}) ①
,
>>> is_it_true({'a': 1}) ②
,
① | . |
② | . |
None
None Python. . None , False. None 0. None . None , False.
None . None (NoneType). None , NoneType. , None .
>>> type(None)
<class 'NoneType'>
>>> None == False
False
>>> None == 0
False
>>> None == ''
False
>>> None == None
True
>>> x = None
>>> x == None
True
>>> y = None
>>> x == y
True
|
|
None
None , not None .
>>> def is_it_true(anything):
... if anything:
... print(", ")
... else:
... print(", ")
...
>>> is_it_true(None)
,
>>> is_it_true(not None)
,
- -
- -
- -
- fractions
- math
- PEP 237:
- PEP 238:
, , , , , , , . |
, , . , , ( , - ). , , . , , .