As far as I understand, you want want the iterator to return a vector of references into itself, right? Unfortunately, it is not possible in Rust. This is the trimmed down Iterator trait: trait Iterator { type Item; fn next(&mut self) -> Option<Item>; } Note that there is no lifetime connection between &mut self and … Read more
iter() is an iterator over a sequence. [x] * n produces a list containing n quantity of x, i.e. a list of length n, where each element is x. *arg unpacks a sequence into arguments for a function call. Therefore you’re passing the same iterator 3 times to zip(), and it pulls an item from … Read more
iterator is a more general concept: any object whose class has a __next__ method (next in Python 2) and an __iter__ method that does return self. Every generator is an iterator, but not vice versa. A generator is built by calling a function that has one or more yield expressions (yield statements, in Python 2.5 … Read more
Python 2.6+ and Python 3: If you want StopIteration to be raised if no matching element is found: next(x for x in the_iterable if x > 3) If you want default_value (e.g. None) to be returned instead: next((x for x in the_iterable if x > 3), default_value) Note that you need an extra pair of … Read more
I debated answering this for a while, because similar questions have been asked many times here. But it’s just unique enough to be given the benefit of the doubt. (Still, I won’t object if others vote to close.) Here’s a visual explanation of what is happening. [0, 1, 2, 3, 4, 5, 6, 7, 8, … Read more
Use an Iterator and call remove(): Iterator<String> iter = myArrayList.iterator(); while (iter.hasNext()) { String str = iter.next(); if (someCondition) iter.remove(); }
Python 3.6 version of the above answer, using os – assuming that you have the directory path as a str object in a variable called directory_in_str: import os directory = os.fsencode(directory_in_str) for file in os.listdir(directory): filename = os.fsdecode(file) if filename.endswith(“.asm”) or filename.endswith(“.py”): # print(os.path.join(directory, filename)) continue else: continue Or recursively, using pathlib: from pathlib import … Read more
To safely remove from a collection while iterating over it you should use an Iterator. For example: List<String> names = …. Iterator<String> i = names.iterator(); while (i.hasNext()) { String s = i.next(); // must be called before you can call i.remove() // Do something i.remove(); } From the Java Documentation : The iterators returned by … Read more
Iterators (e.g. from calling iter, from generator expressions, or from generator functions which yield) are stateful and can only be consumed once, as explained in Óscar López’s answer. However, that answer’s recommendation to use itertools.tee(data) instead of list(data) for performance reasons is misleading. In most cases, where you want to iterate through the whole of … Read more
Iterator objects in python conform to the iterator protocol, which basically means they provide two methods: __iter__() and __next__(). The __iter__ returns the iterator object and is implicitly called at the start of loops. The __next__() method returns the next value and is implicitly called at each loop increment. This method raises a StopIteration exception … Read more