Are you asking about a way to walk through a directory and find gdb's? One way:
import arcpy, os
from arcpy import env
workspace = r"C:\Path\to\explore"
for dirpath, dirnames, filenames in arcpy.da.Walk(workspace, datatype="Container"):
for dirname in dirnames:
if ".gdb" in dirname:
env.workspace = os.path.join(dirpath, dirname)
tableList = arcpy.ListFeatureClasses()
for table in tableList:
print "{}\t{}\t{}".format(dirpath, dirname, table)