Iterators:

Iterator are objects which uses next() method to get next value of sequence.

Generators:

A generator is a function that produces or yields a sequence of values using yield method.

Every next() method call on generator object(for ex: f as in below example) returned by generator function(for ex: foo() function in below example), generates next value in sequence.

When a generator function is called, it returns an generator object without even beginning execution of the function. When next() method is called for the first time, the function starts executing until it reaches yield statement which returns the yielded value. The yield keeps track of i.e. remembers last execution. And second next() call continues from previous value.

The following example demonstrates the interplay between yield and call to next method on generator object.

>>> def foo(): ... print "begin" ... for i in range(3): ... print "before yield", i ... yield i ... print "after yield", i ... print "end" ... >>> f = foo() >>> f.next() begin before yield 0 # Control is in for loop 0 >>> f.next() after yield 0 before yield 1 # Continue for loop 1 >>> f.next() after yield 1 before yield 2 2 >>> f.next() after yield 2 end Traceback (most recent call last): File "<stdin>", line 1, in <module> StopIteration >>> 

Iterators are objects which use the next() method to get the following values of a sequence.

Generators are functions that produce or yield a sequence of values using the yield keyword.

Every next() method call on a generator object(for ex: f below) returned by a generator function  (for ex: foo() below), generates the next value in the sequence.

When a generator function is called, it returns an generator object without even beginning the execution of the function. When the next() method is called for the first time, the function starts executing until it reaches a yield statement which returns the yielded value. The yield keeps track of what has happened, i.e. it remembers the last execution. And secondly, the next() call continues from the previous value.

The following example demonstrates the interplay between yield and the call to the next method on a generator object.

>>> def foo(): ... print("begin") ... for i in range(3): ... print("before yield", i) ... yield i ... print("after yield", i) ... print("end") ... >>> f = foo() >>> next(f) begin before yield 0 # Control is in for loop 0 >>> next(f) after yield 0 before yield 1 # Continue for loop 1 >>> next(f) after yield 1 before yield 2 2 >>> next(f) after yield 2 end Traceback (most recent call last): File "<stdin>", line 1, in <module> StopIteration 

Iterators:

Iterator are objects which uses next() method to get next value of sequence.

Generators:

A generator is a function that produces or yields a sequence of values using yield method.

Every next() method call on generator object(for ex: f as in below example) returned by generator function(for ex: foo() function in below example), generates next value in sequence.

When a generator function is called, it returns an generator object without even beginning execution of the function. When next() method is called for the first time, the function starts executing until it reaches yield statement which returns the yielded value. The yield keeps track of i.e. remembers last execution. And second next() call continues from previous value.

The following example demonstrates the interplay between yield and call to next method on generator object.

>>> def foo(): ... print "begin" ... for i in range(3): ... print "before yield", i ... yield i ... print "after yield", i ... print "end" ... >>> f = foo() >>> f.next() begin before yield 0 0 >>> f.next() after yield 0 before yield 1 1 >>> f.next() after yield 1 before yield 2 2 >>> f.next() after yield 2 end Traceback (most recent call last): File "<stdin>", line 1, in <module> StopIteration >>> 

Iterators:

Iterator are objects which uses next() method to get next value of sequence.

Generators:

A generator is a function that produces or yields a sequence of values using yield method.

Every next() method call on generator object(for ex: f as in below example) returned by generator function(for ex: foo() function in below example), generates next value in sequence.

When a generator function is called, it returns an generator object without even beginning execution of the function. When next() method is called for the first time, the function starts executing until it reaches yield statement which returns the yielded value. The yield keeps track of i.e. remembers last execution. And second next() call continues from previous value.

The following example demonstrates the interplay between yield and call to next method on generator object.

>>> def foo(): ... print "begin" ... for i in range(3): ... print "before yield", i ... yield i ... print "after yield", i ... print "end" ... >>> f = foo() >>> f.next() begin before yield 0 # Control is in for loop 0 >>> f.next() after yield 0  before yield 1 # Continue for loop 1 >>> f.next() after yield 1 before yield 2 2 >>> f.next() after yield 2 end Traceback (most recent call last): File "<stdin>", line 1, in <module> StopIteration >>>