Missing argument in lambda function

Tutorial script recentfiles.py is missing argument in lambda function in line 21.
```python
for f in recent_files:
    menu_recent.add_command(label=os.path.basename(f), command=lambda : openFile(f))
```

The book has the correct version
```python
for f in recent_files:
    menu_recent.add_command(label=os.path.basename(f), command=lambda f=f : openFile(f))
```
