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Python – next()
Python next() built-in function returns the next item from the iterator object by calling iterator’s __next__() method.
In this tutorial, we will learn the syntax and usage of next() built-in function with examples.
Syntax
The syntax of next() function is
next(iterator)
next(iterator, default)where
| Parameter | Mandatory/ Optional | Description |
|---|---|---|
| iterator | Mandatory | A Python iterator object. |
| default | Optional | Default value that next() has to return if there is no next item in the iterator. |
Examples
1. Get next objects from iterator
In the following program, we take a list in myList, get its iterator using the iter() built-in function, and print the next items in the iterator using next().
Python Program
myList = ['apple', 'banana', 'cherry']
myIterator = iter(myList)
print(next(myIterator))
print(next(myIterator))
print(next(myIterator))Output
apple
banana
cherry2. Get next objects from iterator with Default value
In the following program, we make a call to the next() function with iterator and default value passed as arguments.
When there are no next() elements to return from the iterator object, next() returns the default value.
Python Program
myList = ['apple', 'banana', 'cherry']
myIterator = iter(myList)
print(next(myIterator, 'NA'))
print(next(myIterator, 'NA'))
print(next(myIterator, 'NA'))
print(next(myIterator, 'NA'))
print(next(myIterator, 'NA'))Output
apple
banana
cherry
NA
NAWe have exhausted the items in the iterator in the first three calls. For the last two next() function calls, there are no items in the iterator. Therefore, next() has returned the default value with is the string 'NA'.
Related Tutorials
Summary
In this Built-in Functions tutorial, we learned the syntax of the next() built-in function, and how to use this function to get the next value from an iterator object, with examples.