Python like Java is open source, MS is horrified by this. They had to use Java because of the Internet Explorer. Look what they tried to do to Java a few years ago to make it their own, SUN had to sue them to stop it.
For Each ctrl As Control In Me.Controls("pnlMainPanel").Controls
If ctrl.GetType Is GetType(System.Windows.Forms.Panel) Then
For Each subCtrl As Control In ctrl.Controls
If subCtrl.GetType Is GetType(System.Windows.Forms.TextBox) Then
If subCtrl.GetType Is ...