What is Yield in Python?
The term "yield" is used in the context of generator functions in the Python programming language. Iterators may be created using a particular class of functions called generator functions. Let's see a simple illustration to understand better how "yield" functions:
def generator_function():
yield 1
yield 2
yield 3
The generator function 'generator_function()' has been defined in the code above. The "yield" keyword is used within this function to provide the values that the generator will output. The values 1, 2, and 3 will be produced in this scenario.
Now, unlike a usual function, this one doesn't start running instantly when we call it. On the contrary, an iterator object is returned:
generator = generator_function()
We may use the 'next()' method or a loop to cycle across the values produced by the generator:
print(next(generator)) # Output: 1
print(next(generator)) # Output: 2
print(next(generator)) # Output: 3
The 'next()' method requests the generator's succeeding value. You can see that the generator preserves its internal state by producing one value at a time and pausing its execution. When 'next()' is used again, it picks up where it left off and generates the next value. When no more values are left to give, this cycle repeats itself and throws the "StopIteration" exception.
Generators are helpful when working with significant volumes of data or when the whole set of values is not known in advance. Producing and processing values as needed provides a memory-effective method of iterating through such data.
Additionally, "yield" may be used to get data from the caller. A generator accepts a value provided to it using the "send()" function, picks up where it left off in its execution, and continues.
You may produce a series of values by repeatedly using the yield statement within a generator function. Additionally, you may build more complicated behaviors within the generator function by using conditional statements, loops, and other control flow structures.
Overall, Python's "yield" function is a strong tool that allows it to build iterators and generators, allowing you to construct memory-friendly, effective code for handling massive or dynamically produced data sets.
Difference between Yield and Return Function in Python
When returning data from a function in Python, the phrases "yield" and "return" are used, although they vary significantly in functionality and behavior.
| Terms | Yield | Return |
| Function Type | "yield" is used in generator functions to specify the values that will be created and to halt the function's execution so that it may be continued later. | "return" function returns a value and ends the function's execution. |
| Execution Behavior | "Yield" briefly pauses the function, remembers its state, and produces a result. The function picks off where it left off the next time it is called, maintaining its internal state. | The command "return" ends the execution of the function and returns a single value. The function ends when "return" is met; no further code is run afterward. |
| Usage in Functions | Several times throughout a generator function, "yield" is used to specify the values that will be created. It can't be utilized in normal functions and must be utilized in the body of a generator function. | In a standard function, "return" is often used once or twice to return values. Anywhere in the function body may contain it. |
| Return Type | "Yield" does not end the function but returns a value. The generator creates the returned value, which may be of any type. | "Return" leaves the function while returning a value. Any kind of value, including integers, strings, lists, and other objects, may be included in the returned result. |
| Iteration and Generators | The concept of "yield" is crucial for building generators. An iterator object that may be iterated through to create demand values is returned by a generator function when it is invoked. The iterator generates a value each time the generator gives one. | It is not possible to build iterators or generators using "return". |
In conclusion, "yield" is used to specify values that will be created and halt the execution of a generator function, enabling it to be continued later, whereas "return" is used to return a value and end a normal function. In particular, "yield" builds generators and facilitates iteration across dynamically produced or huge data collections.