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list(1) isn't iterable, but list('a') is. Quirk of Python or is there a reason for this?


1 Answer

Chris Freeman
Chris Freeman
Treehouse Moderator 68,423 Points

This is a case where list() is not the same as using bare brackets [ ] to define a list. The built-in function list() iterates over an single object and returns a list of the objects items. The brackets [ ] creates a list from the literal and object references listed between the brackets.

To get a list of of the number 1 using the list() function pass the integer as a tuple:

$ python3
Python 3.4.3 (default, Oct 14 2015, 20:28:29) 
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> list(1)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'int' object is not iterable
>>> list((1, ))

Cool, thanks.