Creating fishnet from template feature class using ArcPy?

here is an example. You need to extract the bounding box from a describe object.

desc = arcpy.Describe(fc)
arcpy.CreateFishnet_management(fc[:-4]+"_c200.shp",str(desc.extent.lowerLeft),str(desc.extent.XMin) + " " + str(desc.extent.YMax + 10),"200","200","0","0",str(desc.extent.upperRight),"NO_LABELS","#","POLYGON")

Here is an alternate approach that I used to create multiple fishnets within the extents of each feature within a feature class. The search_extents variable defines the path to that feature class defining the extents of each fishnet I wanted to create. There was no rotation of the fishnet.

search_extents = "path to extents" 
rows = arcpy.SearchCursor(search_extents)
shapeName = arcpy.Describe(search_extents).shapeFieldName
for row in rows:
    print("Starting Extent" + row.getValue("Extent_Num"))
    feat = row.getValue(shapeName)
    extent = feat.extent
    arcpy.CreateFishnet_management(arcpy.env.workspace + "/extents/extentgrid" + row.getValue("Extent_Num"),str(extent.lowerLeft), str(extent.upperLeft),"0","0","200","200",str(extent.upperRight),"NO_LABELS","#","POLYGON")
    print("Finishing Extent" + row.getValue("Extent_Num"))