chancging string formating method + bigfix (output_f) + spelling

Here is another tip just for your own information! If you define the method `__str__` for your object, the object will execute that function when you use it with the print() function. So for example:

If you have an object with no __str__ method, like this one:
```python
class MyObject(object):
    pass
```
and you try to print it, you get:
```
>>> print("I'm {} with Python!".format(MyObject())) 
I'm <__main__.MyObject object at 0x2ade1bf3fd50> with Python!
```

__but__ if you give your object a `__str__ `method!:
```python
class MyBetterObject(object)
    def __str__(self):
        return "pretty good"
```
then you can control how it prints!:
```
>>> print("I'm {} with Python!".format(MyBetterObject())) 
I'm pretty good with Python!
```

```python
class MyObj(object):
    def __str__(self):
        return "String value"
```

so this would be instead of typing `print("{}".format(self.name))`. Again, not that important but a good example!