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is a str object a valid iterator? - Skaperen - Jan-27-2020
is a str object a valid iterator?
RE: is a str object a valid iterator? - DeaD_EyE - Jan-27-2020
In [1]: next('Foo')
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-1-60a92f7bb96c> in <module>
----> 1 next('Foo')
TypeError: 'str' object is not an iteratorNo, it's an iterable, but not an iterator.
RE: is a str object a valid iterator? - perfringo - Jan-27-2020
(Jan-27-2020, 02:13 AM)DeaD_EyE Wrote: No, it's an iterable, but not an iterator.
..and to make iterator from iterable there is built-in function iter():
>>> next(iter('42'))
'4'
RE: is a str object a valid iterator? - DeaD_EyE - Jan-27-2020
Yes, but you should have a reference to the iterator:
greeting = "Hello World" iterator = iter(greeting) print(next(iterator)) print(next(iterator))If you do
next(iter('42')) two times, you'll get 4 two times.
RE: is a str object a valid iterator? - perfringo - Jan-27-2020
(Jan-27-2020, 09:18 AM)DeaD_EyE Wrote: If you do next(iter('42')) two times, you'll get 4 two times.Yes, you are absolutely right. There is ambiguity in my post, it was too much about next() and not about practical application.
Just to add one more tidbit: for-loop creates iterator from iterable 'behind the scenes'.
RE: is a str object a valid iterator? - DeaD_EyE - Jan-27-2020
Yes, this is one fact, that many people don't know.
for element in "abc":
passis the same likefor element in iter("abc"):
passThe first one is implicit, the second explicit.I use "explicit" iterators often in while-loops.
RE: is a str object a valid iterator? - Skaperen - Jan-27-2020
(Jan-27-2020, 02:13 AM)DeaD_EyE Wrote: No, it's an iterable, but not an iterator.my bad; i should have said "iterable".
is it treated as an iterable by itertools.chain?