TastyHint2.md
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Eredeti
If we have thought about this:
```python
tasks = {} # creates an empty dictionary
tasks['Buy Milk'] = 'not yet'
tasks['Start Lab'] = 'completed'
tasks['Finish Lab'] = 'not yet'
# to test if something is done?
task_name = 'Buy Milk'
if tasks[task_name] == 'not yet':
# task is unfinished
pass
else:
# task is 'complete'
pass
# to list all the tasks
for task_name, status in tasks.items():
print("- ", task_name, status)
```
We need to think about how to put thse ideas _into the class_.
We might...
```python
class Tasty:
def __init__(self):
self.tasks = {}
def add_task(self, task_name):
"""
Add a new task to the user tasks.
"""
if task_name not in self.tasks:
self.tasks[task_name] = "not yet"
else:
print("Task already added.")
def display_tasks(self):
for task_name, status in self.tasks.items():
print("- ", task_name, status)
```
See how those things went from just trial code to _methods_ in the class?
Yes, and... the `self` variable is how you know that thing is a _method_ and not just a _function_.
If I paste the second code block into a Python interpreter...
```bash
>>> class Tasty:
...
... def __init__(self):
... self.tasks = {}
...
... def add_task(self, task_name):
... """
... Add a new task to the user tasks.
... """
... if task_name not in self.tasks:
... self.tasks[task_name] = "not yet"
... else:
... print("Task already added.")
...
...
... def display_tasks(self):
... for task_name, status in enumerate(self.tasks.items()):
... print("- ", task_name, status)
...
...
>>> t = Tasty()
>>> t.add_task("Foo")
>>> t.add_task("Bar")
>>>
>>> t.display_tasks()
- 0 ('Foo', 'not yet')
- 1 ('Bar', 'not yet')
>>>
```
That's an example of how I might use the rough class here.
And if you're puzzled about my use of `enumerate` - I think now that it is wrong. It should probably be...
```python
def display_tasks(self):
for task_name, status in self.tasks.items():
print("- ", task_name, status)
```
If we have thought about this:
tasks = {} # creates an empty dictionary
tasks['Buy Milk'] = 'not yet'
tasks['Start Lab'] = 'completed'
tasks['Finish Lab'] = 'not yet'
# to test if something is done?
task_name = 'Buy Milk'
if tasks[task_name] == 'not yet':
# task is unfinished
pass
else:
# task is 'complete'
pass
# to list all the tasks
for task_name, status in tasks.items():
print("- ", task_name, status)
We need to think about how to put thse ideas into the class. We might...
class Tasty:
def __init__(self):
self.tasks = {}
def add_task(self, task_name):
"""
Add a new task to the user tasks.
"""
if task_name not in self.tasks:
self.tasks[task_name] = "not yet"
else:
print("Task already added.")
def display_tasks(self):
for task_name, status in self.tasks.items():
print("- ", task_name, status)
See how those things went from just trial code to methods in the class?
Yes, and... the self variable is how you know that thing is a method and not just a function.
If I paste the second code block into a Python interpreter...
>>> class Tasty:
...
... def __init__(self):
... self.tasks = {}
...
... def add_task(self, task_name):
... """
... Add a new task to the user tasks.
... """
... if task_name not in self.tasks:
... self.tasks[task_name] = "not yet"
... else:
... print("Task already added.")
...
...
... def display_tasks(self):
... for task_name, status in enumerate(self.tasks.items()):
... print("- ", task_name, status)
...
...
>>> t = Tasty()
>>> t.add_task("Foo")
>>> t.add_task("Bar")
>>>
>>> t.display_tasks()
- 0 ('Foo', 'not yet')
- 1 ('Bar', 'not yet')
>>>
That's an example of how I might use the rough class here.
And if you're puzzled about my use of enumerate - I think now that it is wrong. It should probably be...
def display_tasks(self):
for task_name, status in self.tasks.items():
print("- ", task_name, status)