title: a Python nesting For loop iterating through an ESRI List
body: <p>Sorry to ask such a basic question but:</p>
  
  <p>I've tried repeatedly to iterate through a nested Python loop with no success.  The objective is to peer into each Feature Dataset (about 25 of them) and extract all Feature Classes, then concatenate as such: Buildings / structures_existing_area etc.</p>
  
  <p>This is the best I've done but it doesn't work.</p>
  
  <pre><code>import arcpy
  
  gdb = "U:/GeoDatabases/Bragg_MASTER_FileGeoDataBase10.gdb" 
  arcpy.env.workspace = gdb
  
  def listFcsInGDB():
      for fds in arcpy.ListDatasets('','feature') + ['']:
          for fc in arcpy.ListFeatureClasses('','',fds):
              print (fds +" / "+fc)
  </code></pre>
  
  <p>Thanks in advance.
  Stacy</p>