A list of built-in method
1. The value of the index, the index modification value
lt = [1,2,3,4]
print(lt[1])
lt[1] = 3
print(lt)2
[1, 3, 3, 4]
2. Slice
print(lt[:])#冒号左边没有左边取到头，右边没有则右边取到头
print(lt[1:2])#顾头不顾尾，只打印索引号为1的元素
print(lt[1:4:2])#步长为2[1, 3, 3, 4]
[3]
[3, 4]
3.for cycle
for i in lt:
print(i**2)#打印列表每一个值的幂1
9
9
16
4. The members of the operation
print(1 in lt)
print(5 in lt)True
False
5.append()
lt.append(5)#往列表的最后一位添加元素
print(lt)[1, 3, 3, 4, 5]
6.len
print(len(lt))5
7.del Delete (delete the specified index number of the element)
print(lt)
del lt[0]
print(lt)[1, 3, 3, 4, 5]
[3, 3, 4, 5]
8.insert
lt=[1,2,3,4,5]
lt.insert(0,0)#向前插入
print(lt)[0, 1, 2, 3, 4, 5]
9.pop deleted in accordance with the index value
lt = [11,22,33,44,55]
lt.pop(0)
print(lt)[22, 33, 44, 55]
10.remove delete the value by value
lt.remove(22)
print(lt)[33, 44, 55]
11.count count
lt = [11,11,11,22]
print(lt.count(11))3
12.index looking index values
print(lt.index(11))#找到了就返回0
13.clear Clear List
lt = [1,2,3,4,5]
lt.clear()
print(lt)[]
14.copy copy list
lt = [1,2,3,4]
lt1 = lt.copy()
print(lt1)[1, 2, 3, 4]
15.extend extended list
lt1 = [1,2,3]
lt2 = [4,5,6]
lt1.extend(lt2)
print(lt1)[1, 2, 3, 4, 5, 6]
16.reverse () reverse list
lt = [1,2,3,4]
lt.reverse()
print(lt)[4, 3, 2, 1]
Sort 17.sort
sort () function is used to sort the list of the original, if the parameter is specified using the comparison function specified comparison function.
grammar
sort () method syntax:
list.sort(cmp=None, key=None, reverse=False)parameter
- cmp - optional parameter, if this parameter is a method of using the parameter designated for sorting.
- key - is mainly used for the comparison element, only one parameter, the specific parameter is a function of iteration may be taken from the object, specify one of the elements in the iteration to be sorted.
- reverse - collation, Reverse = True descending, Reverse = False ascending (default).
lt = [2,3,1,0,4]
lt.sort(reverse=True)
print(lt)[4, 3, 2, 1, 0]
Ordered or disordered: Ordered
Variable or immutable: variable
Bubble sort
for i in range(len(lt)):
for j in range(len(lt)):
if lt[i]<lt[j]:
lt[i],lt[j] = lt[j],lt[i]
print(lt)[0, 1, 2, 3, 4]