驗證坐標是否合法

def is_valid_coordinates(coordinates):
    import re
    pattern = re.compile('''\s*  
                            -?\d{1,3}(.\d+)?
                            ,\s*      
                            -?\d{1,3}(.\d+)?
                            $''', re.X)  
    result = pattern.match(coordinates)
    if result:
        x, y = result.group().split(',')
        if abs(float(x)) <= 90 and abs(float(y)) <= 180:
            return True
        else:
            return False
    else:
        return False