Phthon list(转)

简单总结以及整理如下： 

>>> dir(list)
['__add__', '__class__', '__contains__', '__delattr__', '__delitem__', '__delslice__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__getslice__', '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__iter__', '__le__', '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__reversed__', '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__sizeof__', '__str__', '__subclasshook__', 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort']

 

引用
append(...) 
    L.append(object) -- append object to end 

count(...) 
    L.count(value) -> integer -- return number of occurrences of value 

extend(...) 
    L.extend(iterable) -- extend list by appending elements from the utterable 

index(...) 
    L.index(value, [start, [stop]]) -> integer -- return first index of value. 
    Raises ValueError if the value is not present. 

insert(...) 
    L.insert(index, object) -- insert object before index 

pop(...) 
    L.pop([index]) -> item -- remove and return item at index (default last). 
    Raises IndexError if list is empty or index is out of range. 

remove(...) 
    L.remove(value) -- remove first occurrence of value. 
    Raises ValueError if the value is not present. 

reverse(...) 
    L.reverse() -- reverse *IN PLACE* 

sort(...) 
    L.sort(cmp=None, key=None, reverse=False) -- stable sort *IN PLACE*; 
    cmp(x, y) -> -1, 0, 1

 

列表推导(list comprehensions) 

>>> [i for i in range(10) if i%2==0]
[0, 2, 4, 6, 8]
　

>>> def f(x):return x%2!=0 and x%3!=0
>>> filter(f, range(2,25))            　　# filter返回最终值为True的value的list
　　[5, 7, 11, 13, 17, 19, 23]

>>> seq = range(8)
>>> def add(x,y):return x+y 
>>> map(add, seq, seq)
　　[0, 2, 4, 6, 8, 10, 12, 14]           # map 会去遍历后面的值然后依次执行函数

>>> map(lambda x,f = lambda x,f:f(x-1,f)+f(x-2,f) if x >1 else x:f(x,f),range(10))
　　[0, 1, 1, 2, 3, 5, 8, 13, 21, 34]

>>> def add(x,y):return x+y

>>> reduce(add,range(1,11))           　　# reduce会将上一次的结果保存下来作为x，并参与与下一个值y的运算中去
　　55

#用传给reduce中的函数 func()（必须是一个二元操作函数）先对集合中的第1，2个数据进行操作，得到的结果再与第三个数据用func()函数运算，最后得到一个结果

 
>>> def sum(seq):
　　　　def add(x,y):return x+y
　　　　　return reduce(add, seq, 0)

>>> sum(range(1,11))
　　55
>>> sum([])
　　0

 

use enumerate 

>>> seq  = ["one", "two", "three"]
>>> for i, element in enumerate(seq):
...     print i, element
...
0 one
1 two
2 three

 

用Lists作为Stacks 

>>> stack = [3,4,5]
>>> stack.append(6)
>>> stack.append(7)
>>> stack
[3, 4, 5, 6, 7]
>>> stack.pop()
7
>>> stack
[3, 4, 5, 6]
>>> stack.pop()
6
>>> stack
[3, 4, 5]
>>> stack.pop()
5
>>> stack
[3, 4]

 

用Lists作为Queues 

>>> from collections import deque
>>> queue = deque(["Eric", "John", "Michael"])
>>> queue.append("Terry")
>>> queue.append("Graham")
>>> queue.popleft()
'Eric'
>>> queue.popleft()
'John'
>>> queue
deque(['Michael', 'Terry', 'Graham'])

 

Functional Programming Tools 

>>> def f(x):return x%2!=0 and x%3!=0
...
>>> filter(f, range(2,25))
[5, 7, 11, 13, 17, 19, 23]

>>> seq = range(8)
>>> def add(x,y):return x+y
...
>>> map(add, seq, seq)
[0, 2, 4, 6, 8, 10, 12, 14]

>>> map(lambda x,f = lambda x,f:f(x-1,f)+f(x-2,f) if x >1 else x:f(x,f),range(10))
[0, 1, 1, 2, 3, 5, 8, 13, 21, 34]

>>> def add(x,y):return x+y
...
>>> reduce(add,range(1,11))
55

>>> def sum(seq):
...     def add(x,y):return x+y
...     return reduce(add, seq, 0)
...
>>> sum(range(1,11))
55
>>> sum([])
0

 

 

Nested List Comprehensions 

>>> matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]]
>>> [[row[i] for row in matrix] for i in range(4)]
[[1, 5, 9], [2, 6, 10], [3, 7, 11], [4, 8, 12]]

 

The del statement 

>>> a = [1,2,3,4,5,6,7,8,9,0]
>>> del a[0]
>>> a
[2, 3, 4, 5, 6, 7, 8, 9, 0]
>>> del a[2:4]
>>> a
[2, 3, 6, 7, 8, 9, 0]
>>> del a[:]
>>> a
[]

 

Tuples and Sequences 

>>> empty = ()
>>> singleton = 'hello',
>>> len(empty)
0
>>> len(singleton)
1
>>> singleton
('hello',)
>>> t=1,2,3
>>> t
(1, 2, 3)
>>> x, y,z = t

 

Sets 

#Similarly to list comprehensions, set comprehensions are also supported: 

>>> a = {x for x in 'abracadabra' if x not in 'abc'}
>>> a
set(['r', 'd']) 

 

 

取两个list的交集和差集 

>>> l1=[1,2,3,4,5,6,7,8,9,0]
>>> l2=[2,4,6,8]
>>> list(set(l1).intersection(l2))
[8, 2, 4, 6]
>>> list(set(l1).difference(l2))
[0, 1, 3, 5, 7, 9]

 

 

切片操作/索引

>>> l = ['abc', 'def', 'ghi', 123] 
>>> l[2] 
'ghi' 
>>> l[-3] 
'def' 
>>> l[:3] 
['abc', 'def', 'ghi'] 
>>> l[1] = 'haha' 
>>> l 
['abc', 'haha', 'ghi', 123] 
>>> l[1:] = ['apple', 'banana'] 
>>> l 
['abc', 'apple', 'banana'] 
>>> l[2] = [123, 345, 456] 
>>> l 
['abc', 'apple', [123, 345, 456]] 
>>> l[1:] = [123, 234, 345, 456, 567] 
>>> l 
['abc', 123, 234, 345, 456, 567]

 

-------------------------------------------

l[a:b]　　　　　　　　　　# 从index为a开始取，直到index为b-1
l[::-1]　　　　　　　　　　# 相当于l.reverse()之后l的值，也就是说不会产生新的list

 

参考资料: 
Expert Python Programming 
http://docs.python.org/2/tutorial/datastructures.html#more-on-lists