一级文件夹下存在多个GDB，每个GDB存在多个要素类，要求对所有要素类重命名为:"GDB名_原数据名"，如下图：

arcpy.env.workspace = "D:/.../一级文件夹"
wks = arcpy.ListWorkspaces(workspace_type="FileGDB")
for wk in wks:
    arcpy.env.workspace = wk
    fcs = arcpy.ListFeatureClasses()
    for fc in fcs:
        wkname = os.path.basename(wk)[:-4] # 去掉.gdb后缀
        newname = "_".join([wkname, fc])
        arcpy.Rename_management(in_data=fc, out_data=newname)

一级文件下的所有GDB中的所有要素类重命名