arcgis 10.2 - Checking if layers in dataframe using ArcPy?

I working on mxd (I work with ArcMap 10.2.2 & python 2.7.5.) that have 100 layers. I'm trying with python script to add layers to dataframe and check if the layers are within the dataframe. if it within I want that python will add the layers to the table of content, and if it not within the dataframe- the python will remove the layers. Manually I can do it by adding each layer and see if it in the dataframe and then start to choose what to remove, but it will take a lot of time. I also can use this option:

and it also will take a lot of time. I have this script:

import arcpy
from arcpy import env
area= '162000 631000 172000 641000' 
env.workspace = r"C:\project"

for mxdname in arcpy.ListFiles("*.mxd"):
print mxdname
mxd = arcpy.mapping.MapDocument(r"C:\project\\" + mxdname)
df = arcpy.mapping.ListDataFrames(mxd, "Layers")[0] 
df.extent = area
for lyr in arcpy.mapping.ListLayers(mxd, "",df):
    if lyr.name == "residence":
        addLayer = arcpy.mapping.Layer(r"C:\project\layers\residence.lyr")
        arcpy.mapping.AddLayerToGroup(df, lyr, addLayer, "BOTTOM")
        else lyr.dataSource == r"F:\GIS\topo_50000\50000.sid":   

            arcpy.mapping.RemoveLayer(df, lyr)

    if lyr.name == "rivers2":
        addLayer = arcpy.mapping.Layer(r"C:\project\layers\rivers2.lyr")
        arcpy.mapping.AddLayerToGroup(df, lyr, addLayer, "BOTTOM")
mxd.save()
del mxd

I hope someone can describe an easy way to accomplish what I'm after with python script?

Answer

Using the statement below, you could create a temp polygon layer that correspondes to the dataframe extent, iterate and select (select by location) each layer in the map, if selection is > 0 than layer exists within dataframe extent if not then remove.

# create temp polygon layer to dataframe extent
dfAsFeature = arcpy.Polygon(arcpy.Array([df.extent.lowerLeft, df.extent.lowerRight, df.extent.upperRight, df.extent.upperLeft]),df.spatialReference)