python-some useful functions

1.any () function

Any (iterable)->bool

Returns ture if one of the iterators is ture, or False if Interable=null.

>>> any ([1,0])
True
>>> any ([0,0])
False
>>> any ([])
False
>>> any ([1,0,0])
True

Application: In a binary tree, find the largest element in each layer (leetcode515).

Input:           1         /         3   2       /\   \        5   3   9 Output: [1, 3,9] 

#类节点的定义
Classnode (self):def __init__(self,data) Self.val=Data Self.right=NULL Self.left=NULL

classsolution (object):deflargestvalues (self, root): Maxlist=[] Row=[Root] whileAny (row): Maxlist.append (Max[node.val forNodeinchRow]) Row=[kid forNodeinchRow forKidinchNode.left,node.right)ifKid]returnMaxlist

2.all () function

All (iterable)->bool

When each element in the iterator must be true, returns ture, otherwise false.

>>> all ([1,0])
False
>>> All (["E", 1])
True

3.map ()--built-in high-order functions (functions that can accept function names as parameters-higher-order functions)

python-some useful functions