ArcGIS 一級文件夾下所有GDB中的指定要素添加到mxd的圖層中

一級文件夾下存在多個GDB，每個GDB存在多個要素類，要求對名字為frame的要素類，添加到mxd的圖層中顯示 如下圖：

mxd = arcpy.mapping.MapDocument('CURRENT')
df = arcpy.mapping.ListDataFrames(mxd)[0]

arcpy.env.workspace = 'D:/.../一級文件夾'
wks = arcpy.ListWorkspaces(workspace_type="FileGDB")
for wk in wks:   
    arcpy.env.workspace = wk
    features = arcpy.ListFeatureClasses('frame') # 要加載全部要素，修改此處
    for f in features: 
        lyr = arcpy.mapping.Layer(f)
        arcpy.mapping.AddLayer(df,lyr)