python - 如何将变量传递给mapnik数据源类？

Question

我是Python新手，所以请原谅我回答这个新手问题。我有一个类和一个函数:

class Datasource(mapnik.PythonDatasource):
    def __init__(self):
        super(Datasource, self).__init__()

    def features(self, query):
        return mapnik.PythonDatasource.wkb_features(mvt)

def tileLayer(request, version, shapefile_id, zoom, x, y):
    mvt = requestHandler(request, zoom, x, y)

    datasource = mapnik.Python(factory='Datasource')

调用mapnik.Python(factory='Datasource')时，如何将mvt变量传递给Datasource类

Answer 1

您可以向 mapnik.Python 方法添加其他参数 - 它们将被传递到数据源 __init__:

mvt = requestHandler(request, zoom, x, y)
datasource = mapnik.Python(factory='Datasource', mvt=mvt)

向Datasource类__init__方法定义添加参数，并使用它在类实例中保存mvt:

class Datasource(mapnik.PythonDatasource):
    def __init__(self, mvt):
        super(Datasource, self).__init__()
        self.mvt = mvt

    def features(self, query):
        return mapnik.PythonDatasource.wkb_features(self.mvt)