1.操作的類型
concatenation | + | Combine sequences together |
repetition | * | Concatenate a repeated number of times |
membership | in | Ask whether an item is in a sequence |
length | len | Ask the number of items in the sequence |
slicing | [ : ] | Extract a part of a sequence |
‘+’ : 将兩個列結合在一起
例
a = [1, 2, 3]
b = [4, 5, 8]
print a +b
輸出:[1, 2, 3, 4, 5, 8]
‘*’ : 即 重複
例
>>> myList = [0] * 6
>>> myList
[0, 0, 0, 0, 0, 0]
‘ in’ :判斷 是否是其的子集
例
a = [(1, 2),3]
if (1,2) in a:
print a
'len()': 傳回對象(字元、清單、元組等)長度或項目個數
例
>>>str = "runoob"
>>> len(str) # 字元串長度
6
>>> l = [1,2,3,4,5]
>>> len(l) # 清單元素個數
5
‘ [ : ]’ :切片操作包括一個開始下标,一個結束下标,和一個步長(ps:預設值就是集合的開始下标,集合的最後一個元素下标,與步長為1)
>>> L = ['Michael', 'Sarah', 'Tracy', 'Bob', 'Jack']
>>> L[0:3] # 取頭三個元素
['Michael', 'Sarah', 'Tracy']
>>> L[-2:] #從倒數第二個值開始取值
['Bob', 'Jack']
>>> L[-2:-1] #取倒數第二個值 ,最後一個值的下标為 -1,依次往前類推 -2 ,-3...
['Bob']
2.list的使用(ps: 下表 i 表示索引位置, item 表示要操作的對象)
| | 在list末尾添加一個新的item |
| | 将指定對象插入清單的指定位置。 |
| | Removes and returns the last item in a list |
| | Removes and returns the ith item in a list |
| | Modifies a list to be sorted |
| | Modifies a list to be in reverse order |
| | Deletes the item in the ith position |
| | Returns the index of the first occurrence of |
| | Returns the number of occurrences of |
| | Removes the first occurrence of |
myList = [1024, 3, True, 6.5]
myList.append(False)
print(myList) # [1024, 3, True, 6.5, False]
myList.insert(2,4.5)
print(myList) #[1024, 3, 4.5, True, 6.5, False]
print(myList.pop()) # False
print(myList) #[1024, 3, 4.5, True, 6.5]
print(myList.pop(1)) # 3
print(myList) # [1024, 4.5, True, 6.5]
myList.pop(2)
print(myList) # [1024, 4.5, 6.5]
myList.sort()
print(myList) # [4.5, 6.5, 1024]
myList.reverse()
print(myList) # [1024, 6.5, 4.5]
print(myList.count(6.5)) # 1
print(myList.index(4.5)) # 2
myList.remove(6.5)
print(myList) # [1024, 4.5]
del myList[0]
print(myList) # [4.5]