__init__.py 文件源码

def __getitem__(self, index):
        inds = self.indices
        vals = self.values
        if not isinstance(index, int):
            raise TypeError(
                "Indices must be of type integer, got type %s" % type(index))

        if index >= self.size or index < -self.size:
            raise IndexError("Index %d out of bounds." % index)
        if index < 0:
            index += self.size

        if (inds.size == 0) or (index > inds.item(-1)):
            return 0.

        insert_index = np.searchsorted(inds, index)
        row_ind = inds[insert_index]
        if row_ind == index:
            return vals[insert_index]
        return 0.