python 中自己写方法 计算向量长度 / 实现向量归一化

 # coding=utf-8
import math
class Vector(object):
    """docstring for Vector"""
    """根据坐标轴列表输入 创建向量, 并创建该向量所处的空间维度"""
    def __init__(self, coordinates):
        super(Vector, self).__init__()
        try:
            if not coordinates:
                raise ValueError
            self.coordinates = tuple(coordinates)
            self.dimension = len(coordinates)    
        except ValueError:
            raise ValueError('The coordinates must be nonempty')
        except TypeError:
            raise TypeError('The coordinates must be an iterable')

    # '''能够使python的内置print函数 输出向量坐标轴'''

    def __str__(self):
        return 'Vector: {}'.format(self.coordinates)

    def __eq__(self, v):
         return self.coordinates == v.coordinates
    
    # 计算向量长度
    def calculateSize(self):
        result = 0
        num = len(self.coordinates)
        for i  in range(num):
            result +=self.coordinates[i] * self.coordinates[i]
        result = math.sqrt(result)
        return round(result,3)

    # 将向量归一化
    def standardizaiton(self):
        size = self.calculateSize()
        new_corrdinate = [round(x/size,3) for x in self.coordinates]
        return Vector(new_corrdinate)

myVector = Vector([-0.221,7.437])
myVector2 = Vector([5.581,-2.136])
myVector3 = Vector([8.813,-1.331,-6.247])
myVector4 = Vector([1.996,3.108,-4.554])




print myVector.calculateSize()
print myVector2.standardizaiton()
print myVector3.calculateSize()
print myVector4.standardizaiton()
# 输出结果
# 7.44
# Vector: (0.934, -0.357)
# 10.884
# Vector: (0.34, 0.53, -0.777)
# [Finished in 0.1s]
 # coding=utf-8
import math
class Vector(obj