>>> li = [ " a " , " b " , " mpilgrim " , " z " , " example " ]
>>> li
[ ' a ' , ' b ' , ' mpilgrim ' , ' z ' , ' example ' ]
>>> li[0]
' a '
>>> li[ 4 ]
' example '
2、list可以当成数组来用，元素下标从0开始
>>> li
['a', 'b', 'mpilgrim', 'z', 'example']
>>> li[−1]
'example'
>>> li[−3]
'mpilgrim'
（1）当0 <= n <= len(L)-1 时， 跟java、C中的数组元素索引一样
（2）当-len(L) <= n <= -1 时, L[n] = L[len(L)+n]
（3）n不再上述范围内是，程序引发IndexError
li = ['a', 'b', 'String', 'list', 'dictionary']
print li[0:3]
print li[:]
print li[:3]
print li[1:]
print li[0:7] # won't cause IndexError
print li[-2:-1] # identical to li[len(li)-2 : len(li)-1]=li[3:4]
print li[-1:-2] # identical to li[4:3], so it will return a empty list
print li[-125:1159]
['a', 'b', 'String']
['a', 'b', 'String', 'list', 'dictionary']
['a', 'b', 'String']
['b', 'String', 'list', 'dictionary']
['a', 'b', 'String', 'list', 'dictionary']
['list']
[]
['a', 'b', 'String', 'list', 'dictionary']
（1）当 0 <= a < b < len(L)时，L[a:b]返回一个由L[a], L[a+1]...L[b-1]组成的list
（2）当 0 <= b <= a < len(L)时，L[a:b]返回空的list
（3）当a，b取值不在上述范围时，应用以下4条规则替换a，b的值，得到a，b新的值后再应用上面两条规则。
- 若 a >= len(L), 则 a = len(L)-1
- 若 -len(L) <= a < 0, 则 a = len(L) + a
- 若 a < -len(L)， 则 a = 0
- b的情况跟a一样
- 当 a没有指定时，a = 0, 当b没指定时，b=len(L)-1
>>> li = ['a', 'b', 'c']
>>> li.extend(['d', 'e', 'f'])
>>> li
['a', 'b', 'c', 'd', 'e', 'f']
>>> len(li)
6
>>> li[−1]
'f'
>>> li = ['a', 'b', 'c']
>>> li.append(['d', 'e', 'f'])
>>> li
['a', 'b', 'c', ['d', 'e', 'f']]
>>> len(li)
4
>>> li[−1]
['d', 'e', 'f'
6、
Method |
Description |
|---|---|
Nonmutating methods |
|
L.count(x) |
Returns the number of items of L that are equal to x. |
L.index(x) |
Returns the index of the first occurrence of an item in L that is equal to x, or raises an exception if L has no such item. |
Mutating methods |
|
L.append(x) |
Appends item x to the end of L ; e.g., L[len(L):]=[x]. |
L.extend(s) |
Appends all the items of iterable s to the end of L; e.g., L[len(L):]=s. |
L.insert(i, x) |
Inserts item x in L before the item at index i, moving following items of L (if any) "rightward" to make space (increases len(L) by one, does not replace any item, does not raise exceptions: acts just like L[i:i]=[x]). |
L.remove(x) |
Removes from L the first occurrence of an item in L that is equal to x, or raises an exception if L has no such item. |
L.pop([i]) |
Returns the value of the item at index i and removes it from L; if i is omitted, removes and returns the last item; raises an exception if L is empty or i is an invalid index in L. |
L.reverse( ) |
Reverses, in place, the items of L. |
L.sort([f]) (2.3) |
Sorts, in place, the items of L, comparing items pairwise via function f; if f is omitted, comparison is via the built-in function cmp. For more details, see "Sorting a list" on page 57. |
L.sort(cmp=cmp, key=None, reverse=False)(2.4) |
Sorts, in-place, the items of L, comparing items pairwise via the function passed as cmp (by default, the built-in function cmp). When argument key is not None, what gets compared for each item x is key(x), not x itself. For more details, see "Sorting a list" on page 57. |
>>> li = ['a', 'b', 'mpilgrim']
>>> li = li + ['example', 'new']
>>> li
['a', 'b', 'mpilgrim', 'example', 'new']
>>> li += ['two']
>>> li
['a', 'b', 'mpilgrim', 'example', 'new', 'two']
>>> li = [1, 2] * 3
>>> li
[1, 2, 1, 2, 1, 2]
li = ['a']
print li
#li = li + 'b' TypeError: can only concatenate list (not "str") to list
li += 'b'
print li
li = li * 2
print li
li *= 2
print li
['a']
['a', 'b']
['a', 'b', 'a', 'b']
['a', 'b', 'a', 'b', 'a', 'b', 'a', 'b']