def _tile_coords(self, bounds):
tfm = partial(pyproj.transform,<EOL>pyproj.Proj(init="<STR_LIT>"),<EOL>pyproj.Proj(init="<STR_LIT>"))<EOL>bounds = ops.transform(tfm, box(*bounds)).bounds<EOL>west, south, east, north = bounds<EOL>epsilon = <NUM_LIT><EOL>if east != west and north != south:<EOL><INDENT>west += epsilon<EOL>south += epsilon<EOL>east -= epsilon<EOL>north -= epsilon<EOL><DEDENT>params = [west, south, east, north, [self.zoom_level]]<EOL>tile_coords = [(tile.x, tile.y) for tile in mercantile.tiles(*params)]<EOL>xtiles, ytiles = zip(*tile_coords)<EOL>minx = min(xtiles)<EOL>miny = min(ytiles)<EOL>maxx = max(xtiles) <EOL>maxy = max(ytiles)<EOL>return minx, miny, maxx, maxy<EOL>
convert mercator bbox to tile index limits