import numpy as np

array_longi = np.array([x2-x1, y2-y1])
array_trans = np.array([x2-line_start_x, y2-line_start_y])

# 用向量計(jì)算點(diǎn)到直線的舉例
array_temp = (float(array_trans .dot(array_longi)) / array_longi.dot(array_longi))
array_temp = array_longi.dot(array_temp)
distance = np.sqrt((array_trans - array_temp).dot(array_trans - array_temp ))  # 距離

class Point:
    x = 0
    y = 0

    def __init__(self, x=0, y=0):
        self.x = x
        self.y = y

class Line:
    def __init__(self, p1, p2):
        self.p1 = p1
        self.p2 = p2

def GetLinePara(line):
    line.a = line.p1.y - line.p2.y
    line.b = line.p2.x - line.p1.x
    line.c = line.p1.x * line.p2.y - ine.p2.x * line.p1.y 

def GetCrossPoint(l1, l2):
    GetLinePara(l1)
    GetLinePara(l2)
    d = l1.a * l2.c - l2.a * l1.b
    p = Point()
    p.x = (l1.b * l2.c - l2.b * l1.c) * 1.0 /d
    p.y = (l1.c * l2.a - l2.c * l1.a) * 1.0 /d


p1 = Point(1, 1)
p2 = Point(3, 3)
line1 = Line(p1, p2)

p3 = Point(2, 3.1)
p = Point(3.1, 2)
line2 = Line(p3, p4)

Pc = GetCrossPoint(line1, line2)
print(Pc.x, Pc.y)

import numpy as np

def GetCrossAngle(l1, l2):
    arr_0 = np.array([(l1.p2.x - l1.p1.x), (l1.p2.y - l1.p1.y)])
    arr_1 = np.array([(l2.p2.x - l2.p1.x), (l2.p2.y - l2.p1.y)])
    cos_value = (float(arr_0.dot(arr_1)) / (np.sqrt(arr_0.dot(arr_0)) * np.sqrt(arr_1.dot(arr_1))))
    return np.arccos(cos_value) * (180 / np.pi)

angle = GetCrossAngle(line1, line2)  # 計(jì)算得到的角度