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aaron roberts
2,004 Pointsdoes this only work if there is one instance attribute that you want to loop through?
if there was more than one list in the dealership class that you wanted to add to, then iterate through, would this be possible?
3 Answers
Megan Amendola
Treehouse TeacherI'm glad you tested it out! Here's what I tested:
class Car:
def __init__(self):
self.makes = ['ford', 'toyota', 'tesla', 'chevy']
self.types = ['car', 'truck', 'van']
def __iter__(self):
yield from self.makes
car = Car()
for make in car:
print(make)
# result
>>> ford
>>> toyota
>>> tesla
>>> chevy
Dunder iter works on an instance of the class itself. Then I tried:
class Car:
def __init__(self):
self.makes = ['ford', 'toyota', 'tesla', 'chevy']
self.types = ['car', 'truck', 'van']
def __iter__(self):
yield from self.makes
def __iter__(self):
yield from self.types
car = Car()
for make in car:
print(make)
# result
>>> car
>>> truck
>>> van
The second dunder iter overrode the first. Out of curiosity, I tried:
class Car:
def __init__(self):
self.makes = ['ford', 'toyota', 'tesla', 'chevy']
self.types = ['car', 'truck', 'van']
def __iter__(self):
yield from self.makes
yield from self.types
car = Car()
for make in car:
print(make)
# result
>>> ford
>>> toyota
>>> tesla
>>> chevy
>>> car
>>> truck
>>> van
So then I got both lists printed out one after the other. But don't forget that they are lists and can therefore be iterated on themselves. For example:
class Car:
def __init__(self):
self.makes = ['ford', 'toyota', 'tesla', 'chevy']
self.types = ['car', 'truck', 'van']
car = Car()
# access the list itself and then iterate
for make in car.makes:
print(make)
# access the list itself and then iterate
for a_type in car.types:
print(a_type)
# result
>>> ford
>>> toyota
>>> tesla
>>> chevy
>>> car
>>> truck
>>> van
You could also do something like this:
class Car:
def __init__(self):
self.makes = ['ford', 'toyota', 'tesla', 'chevy']
self.types = ['car', 'truck', 'van']
def yield_items(self, item):
if item == 'makes':
yield from self.makes
elif item == 'types':
yield from self.types
car = Car()
for make in car.yield_items('makes'):
print(make)
for a_type in car.yield_items('types'):
print(a_type)
What it comes down to is the structure and organization of your class. What do you want it to do? How do you want it to behave? What makes the most sense?
I hope this helps! That was a fun question to dive into
aaron roberts
2,004 Pointswhen i try to iterate through one specific list that i have added to, it loops through all the attributes (other lists) in the class. is there a way to specify the attribute (list) you want to iterate through?
aaron roberts
2,004 Pointsthanks, i think you covered all ground!
Megan Amendola
Treehouse TeacherMegan Amendola
Treehouse TeacherI encourage you to test it out and see! This is a great way to test your ideas and theories and see what happens. Post back with what you discovered.