List

>>> [41,42,43,44]
[41,42,43,44]
>>> [41,42,43,44] + [41,42,43,44]
[41,42,43,44,41,42,43,44]
>>> len([41,42,43,44])
4
>>> 41 in [41,42,43,44]
True
>>> 41 not in [41,42,43,44]
False
>>> [41,42] in [41,42,43,44]
False
>>> for i in [41,42,43,44]:
        print(i)
41
42
43
44
>>> for i,j in [[41,42],[43,44]]:  # 适用于成对出现的序列
        print(i,j)
41 42
43 44

range

range 是连续数字的序列

>>> list(range(-2,2))
[-2, -1, 0, 1]
>>> list(range(2))
[0, 1]
>>> for _ in range(3):   # 用_表示不关心序列里的值
        print("Go bear!")
Go bear!
Go bear!
Go bear!

列表推导 (List Comprehensions)

>>> odds = [1,3,5]
>>> [x+1 for x in odds]
[2,4,6]
>>> [x for x in odds if 25 % x == 0]
[1,5]
>>> [x+1 for x in odds if 25 % x == 0]
[2,6]

字符串 (Strings)

>>> city = 'Berkeley'
>>> len(city)
8
>>> city[3]
'k'
>>> 'here' in "Where's"
True

切片 (Slice)

• slice 是创建出了新的 list

  >>> odds = [1,3,5,7,9]
  >>> odds[1:3]
  [3, 5]
  >>> odds[:3]
  [1, 3, 5]
  >>> odds[1:]
  [3, 5, 7, 9]
  >>> odds[:]
  [1, 3, 5, 7, 9]

序列函数

sum

sum(iterable, start=0) -> value

• 返回“开始”值(默认值:0)加上一个可迭代的数字，当可迭代为空时，返回开始值。

>>> sum([[2,3],[4]],[])  # 相当于 [] + [2,3] + [4]
[2, 3, 4]

max

max(...) max(iterable, , key=func) -> value max(arg1, arg2, args, [, key=func]) -> value

>>> max(range(10),key = lambda x: 7-(x-4)*(x-2))  # y = 7-(x-4)*(x-2) 当 y 取最大值时， x是？
3

all & any

all(iterable, /) 如果bool(x)对迭代中的所有x都为真，则返回真。 如果可迭代为空，则返回True。 any(iterable, /) 如果bool(x)对迭代中的有一个x为真，则返回真。 如果可迭代为空，则返回False。

>>> all([2,4])
True
>>> all([2,4,0])
False
>>> all([2,4,[]])
False
>>> all([2,4,[1]])
True