17.6: The __str__ method
- Page ID
- 40834
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__str__
is a special method, like __init__
, that is supposed to return a string representation of an object.
For example, here is a str
method for Time objects:
# inside class Time: def __str__(self): return '%.2d:%.2d:%.2d' % (self.hour, self.minute, self.second)
When you print an object, Python invokes the str
method:
>>> time = Time(9, 45) >>> print(time) 09:45:00
When I write a new class, I almost always start by writing __init__
, which makes it easier to instantiate objects, and __str__
, which is useful for debugging.
As an exercise, write a str
method for the Point
class. Create a Point object and print it.