What is the use of the yield keyword in Python? What does it do?
For example, I'm trying to understand this code (**):
def node._get_child_candidates(self, distance, min_dist, madist):
if self._leftchild and distance - madist < self._median:
yield self._leftchild
if self._rightchild and distance + madist >= self._median:
yield self._rightchild
And this is the caller:
result, candidates = list(), [self]
while candidates:
node = candidates.pop()
distance = node._get_dist(obj)
if distance <= madist and distance >= min_dist:
result.extend(node._values)
candidates.extend(node._get_child_candidates(distance, min_dist, madist))
return result
What happens when the method _get_child_candidates is called? A list is returned? A single element is returned? Is it called again? When subsequent calls do stop?
Aryan Kumar
19-Jun-2023The yield keyword in Python is used to create generators. Generators are a special type of function that can be used to produce a sequence of values. When a generator function is called, it does not immediately return a value. Instead, it returns a generator object. The generator object can then be used to iterate over the sequence of values produced by the generator function.
The yield keyword works by suspending the execution of the generator function and returning a value. The state of the generator function is then saved, and the generator object is returned. When the generator object is next iterated over, the execution of the generator function resumes from where it left off.
The yield keyword can be used to create generators that produce any kind of sequence of values. For example, the following code defines a generator function that produces the Fibonacci sequence:
Python
This code first defines a function called
fibonacci()
. The function takes a number as input and returns a generator object that produces the Fibonacci sequence up to the nth term. The function works by first initializing two variables calleda
andb
to 0 and 1, respectively. Then, the function iterates through the numbers from 0 ton
. For each number, the function yields the value ofa
. Then, the function updates the values ofa
andb
.The code then defines a variable called
n
and assigns it the value of 10. The code then calls thefibonacci()
function and stores the result in a variable calledfibonacci_generator
. Finally, the code iterates through the generator object and prints each value to the console.To run the code, you can save it as a Python file and then run it from the command line. For example, if you save the code as
fibonacci.py
, you can run it by typing the following command into the command line:Code snippet
This will print the Fibonacci sequence up to the 10th term to the console.
Anonymous User
11-May-2015