, , if.
>>> def is_it_true(anything):
... if anything:
... print(", ")
... else:
... print(", ")
...
>>> is_it_true(()) ①
,
>>> is_it_true(('a', 'b')) ②
,
>>> is_it_true((False,)) ③
,
>>> type((False)) ④
<class 'bool'>
>>> type((False,))
<class 'tuple'>
① | . |
② | . |
③ | . . ? |
④ | , . Python , , , . |
: Python , .
>>> v = ('a', 2, True)
>>> (x, y, z) = v ①
>>> x
'a'
>>> y
2
>>> z
True
① | v , (x, y, z) . v . |
. , . range() .
>>> (MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY) = range(7) ①
>>> MONDAY ②
0
>>> TUESDAY
1
>>> SUNDAY
6
① | range() . ( , range() , , .) MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY . ( calendar, , , cal UNIX. .) |
② | : MONDAY 0, TUESDAY 1, . |
, , , , . , , , . Python, os, .
|
|
, . . , , , , .
. .
>>> a_set = {1} ①
>>> a_set
{1}
>>> type(a_set) ②
<class 'set'>
>>> a_set = {1, 2} ③
>>> a_set
{1, 2}
① | , ({}). |
② | , -, , . |
③ | , . |
.
>>> a_list = ['a', 'b', 'mpilgrim', True, False, 42]
>>> a_set = set(a_list) ①
>>> a_set ②
{'a', False, 'b', True, 'mpilgrim', 42}
>>> a_list ③
['a', 'b', 'mpilgrim', True, False, 42]
① | , set(). (, , , , . , . , set() .) |
② | , . , , . , . , , . |
③ | . |
? . .
>>> a_set = set() ①
>>> a_set ②
set()
>>> type(a_set) ③
<class 'set'>
>>> len(a_set) ④
0
>>> not_sure = {} ⑤
>>> type(not_sure)
<class 'dict'>
① | , set() . |
② | . , , {}? , . . |
③ | , ... |
④ | ... . |
⑤ | , Python 2, . , , . |
: add() update().
>>> a_set = {1, 2}
>>> a_set.add(4) ①
>>> a_set
{1, 2, 4}
>>> len(a_set) ②
3
>>> a_set.add(1) ③
>>> a_set
{1, 2, 4}
>>> len(a_set) ④
3
① | add() , , . |
② | 3 . |
③ | . , , . ; . |
④ | 3 . |
>>> a_set = {1, 2, 3}
>>> a_set
{1, 2, 3}
>>> a_set.update({2, 4, 6}) ①
>>> a_set ②
{1, 2, 3, 4, 6}
>>> a_set.update({3, 6, 9}, {1, 2, 3, 5, 8, 13}) ③
>>> a_set
{1, 2, 3, 4, 5, 6, 8, 9, 13}
>>> a_set.update([10, 20, 30]) ④
>>> a_set
{1, 2, 3, 4, 5, 6, 8, 9, 10, 13, 20, 30}
|
|
① | update() , . , add() . |
② | , . |
③ | -, update() . , update() ( ). |
④ | update() , . , . |