Setting QTableView column heading

[Rich Shepard]

In a module I import:
from PyQt5 import QtWidgets as qtw
from PyQt5 import QtGui as qtg
from PyQt5 import QtCore as qtc
from PyQt5 import QtSql as qts

For the model I have these statements:
 	self.model = qts.QSqlTableModel()
         self.model.setTable(table_name)
         self.model.setHeaderData(1, Qt.Horizontal, 'Type')
         self.model.select()

When I run the application python tells me:
$ python activitytypes.py 
[]
Traceback (most recent call last):
   File "activitytypes.py", line 49, in <module>
     window = ActTypes()
   File "activitytypes.py", line 29, in __init__
     self.model.setHeaderData(1, Qt.Horizontal, 'Type')
NameError: name 'Qt' is not defined

I haven't found where Qt.Horizontal is defined. Changing Qt to qtw, qtg,
qtc, and qts all generate the same error.

What am I missing?

Rich