计算一个点是否在多边形里 Python 版详解编程语言

[Python]代码    

def isInsidePolygon(pt, poly): 
    c = False 
    i = -1 
    l = len(poly) 
    j = l - 1 
    while i < l-1: 
        i += 1 
        print i,poly[i], j,poly[j] 
        if ((poly[i]["lat"] <= pt["lat"] and pt["lat"] < poly[j]["lat"]) or (poly[j]["lat"] <= pt["lat"] and pt["lat"] < poly[i]["lat"])): 
            if (pt["lng"] < (poly[j]["lng"] - poly[i]["lng"]) * (pt["lat"] - poly[i]["lat"]) / (poly[j]["lat"] - poly[i]["lat"]) + poly[i]["lng"]): 
                c = not c 
        j = i 
    return c 
 
if __name__ == '__main__': 
    abc = [{'lat':1, 'lng':1},{'lat':1, 'lng':4},{'lat':3, 'lng':7},{'lat':4, 'lng':4},{'lat':4, 'lng':1}] 
    print isInsidePolygon({'lat':2, 'lng':5}, abc)