Check if point is inside polygon print True or False using Ray Casting

[Basil Tufail]

i have a code which basically first checks if a point is in a polygon using Ray Casting method and then plots the shapefile. 

what i want  is that the code should only plot the shapefile if the given point lies inside any polygon of the given shapefile.

there is some issue with the first part as it says TRUE even if the point is not inside any polygon of my shapefile

from shapely.geometry import Polygon, Point

import shapefile as shp

import matplotlib.pyplot as plt

polygon = shp.Reader("D:/New folder1/21_8_2016.shp") 

polygon = polygon.shapes()  

shpfilePoints = [ shape.points for shape in polygon ]

polygons = shpfilePoints

for polygon in polygons:

    poly = Polygon(polygon)

lat=15.139078

lon=120.763779

def point_in_poly(x,y,poly):

    n = len(poly)

    inside = True

    

    p1x,p1y = poly[0]

    for i in range(n+1):

        p2x,p2y = poly[i % n]

        if y > min(p1y,p2y):

            if y <= max(p1y,p2y):

                if x <= max(p1x,p2x):

                    if p1y != p2y:

                        xints = (y-p1y)*(p2x-p1x)/(p2y-p1y)+p1x

                    if p1x == p2x or x <= xints:

                        inside = not inside

        

        p1x,p1y = p2x,p2y

        

    return inside

print point_in_poly(lon,lat,polygon)

 

sf = shp.Reader("D:/New folder1/21_8_2016.shp")

plt.figure()

for shape in sf.shapeRecords():

    x = [i[0] for i in shape.shape.points[:]]

    y = [i[1] for i in shape.shape.points[:]]

    plt.plot(x, y, color = 'blue')

plt.scatter(lon, lat, s=10, c='red', zorder=10)

    

plt.show()

the given lat lon in the code are outside any polygon and the following are inside one of  the polygons 

15.094997

120.836563

Attached is also the shapefile