Python Yield
It is generally used to convert a regular Python function into a generator. A generator is a special function in Python that returns a generator object to the caller. Since it stores the local variable states, hence overhead of memory allocation is controlled.
Example:
# Python3 code to demonstrate yield keyword # Use of yielddef printresult(String) : for i in String: if i == "e": yield i # initializing string String = "Lazyroar" ans = 0print ("The number of 'e' in word is : ", end = "" ) String = String.strip() for j in printresult(String): ans = ans + 1 print (ans) |
Output:
The number of 'e' in word is : 4
Python Return
It is generally used for the end of the execution and “returns” the result to the caller statement. It can return all type of values and it returns None when there is no expression with the statement “return”.
Example:
# A Python program to show return statement class Test: def __init__(self): self.str = "GeeksForGeeks" self.x = "Shubham Singh" # This function returns an object of Test def fun(): return Test() # Driver code to test above method t = fun() print(t.str) print(t.x) |
Output:
GeeksForGeeks Shubham Singh
Difference between Python yield and Return
| S.NO. | YIELD | RETURN |
|---|---|---|
| 1 | Yield is generally used to convert a regular Python function into a generator. | Return is generally used for the end of the execution and “returns” the result to the caller statement. |
| 2 | It replace the return of a function to suspend its execution without destroying local variables. | It exits from a function and handing back a value to its caller. |
| 3 | It is used when the generator returns an intermediate result to the caller. | It is used when a function is ready to send a value. |
| 4 | Code written after yield statement execute in next function call. | while, code written after return statement wont execute. |
| 5 | It can run multiple times. | It only runs single time. |
| 6 | Yield statement function is executed from the last state from where the function get paused. | Every function calls run the function from the start. |
