[PY] [Lc]python's Card knowledge points

Module collections-collections.namedtuple means that the tuple is not clear

If it represents a coordinate, T = (up), it is unclear.
If that's the case, point (X=1, y=2)

from collections import namedtuplePoint = namedtuple('Point', ['x', 'y']) #做一些kv形式的易辨别的数据结构p = Point(1, 2)print(p)# Point(x=1, y=2)

Methods of the class: GetItemTo manipulate an instance as a list

class Student:    arr = [0, 1, 2, 3, 4] #返回arr的第3项    def __getitem__(self, n):        return self.arr[n]s = Student()print(s[3])# 3

Class method: The __len__ method is used to measure the length of an instance of a class

class A:    arr = [1, 2, 3] #返回他的长度    def __len__(self):#用来丈量实例长度的        return len(self.arr)a = A()print(len(a))# 3

Some small knowledge points

- str转list>>> list('JQKA')['J', 'Q', 'K', 'A']- 生成str类型的数字序列>>> [str(n) for n in range(2,11)]['2', '3', '4', '5', '6', '7', '8', '9', '10']

Comprehensive small Example

from collections import namedtuplePoint = namedtuple('Point', ['x', 'y'])p = Point(1, 2)print(p)arr1 = [str(i) for i in range(10)]arr2 = [str(i) for i in range(10)]s = [Point(k1,k2) for k1 in arr1 for k2 in arr2]print(s)# Point(x=1, y=2)# [Point(x='0', y='0'), Point(x='0', y='1'), Point(x='0', y='2'), Point(x='1', y='0'), Point(x='1', y='1'), Point(x='1', y='2'), Point(x='2', y='0'), Point(x='2', y='1'), Point(x='2', y='2')]

[PY] [Lc]python's Card knowledge points