python GTK entry: cursor to the left when the entry is empty

Question

I am using a Gtk.Entry and writing from left to right (xalign==0.0). When the entry is not empty, the cursor is to the right of the text (as expected):

But when the entry is empty, the cursor is on the right:

That is how I create the entry:

def CreateUserEntry(self):
    self.user_entry = Gtk.Entry()
    self.user_entry.set_width_chars(10)
    user_label = Gtk.Label(label="User:")
    self.user_entry.set_text(self.args.user)
    self.user_entry.connect('activate', self.ActivateUserTextbox)
    user_box = Gtk.HBox()
    user_box.pack_start(user_label, expand=False, fill=False, padding=10)
    user_box.pack_start(self.user_entry, expand=False, fill=False, padding=0)
    return user_box


def ActivateUserTextbox(self, widget):
    new_user = widget.get_text().strip()
    self.args.user = new_user

How do I fix this? thanks