In Python, we can return multiple values from a function. Following are different ways 1) Using Object: This is similar to C/C++ and Java, we can create a class (in C, struct) to hold multiple values and return an object of the class.
Python
# A Python program to return multiple# values from a method using classclass Test: def __init__(self): self.str = "neveropen" self.x = 20# This function returns an object of Testdef fun(): return Test() # Driver code to test above methodt = fun()print(t.str)print(t.x) |
neveropen 20
Below are interesting methods for somebody shifting C++/Java world.
2) Using Tuple: A Tuple is a comma separated sequence of items. It is created with or without (). Tuples are immutable. See this for details of tuple and list.
Python
# A Python program to return multiple# values from a method using tuple# This function returns a tupledef fun(): str = "neveropen" x = 20 return str, x # Return tuple, we could also # write (str, x)# Driver code to test above methodstr, x = fun() # Assign returned tupleprint(str)print(x) |
neveropen 20
3) Using a list: A list is like an array of items created using square brackets. They are different from arrays as they can contain items of different types. Lists are different from tuples as they are mutable.
Python
# A Python program to return multiple# values from a method using list# This function returns a listdef fun(): str = "neveropen" x = 20 return [str, x]# Driver code to test above methodlist = fun()print(list) |
['neveropen', 20]
4) Using a Dictionary: A Dictionary is similar to hash or map in other languages. See this for details of dictionary.
Python
# A Python program to return multiple# values from a method using dictionary# This function returns a dictionarydef fun(): d = dict(); d['str'] = "Lazyroar" d['x'] = 20 return d# Driver code to test above methodd = fun()print(d) |
{'x': 20, 'str': 'Lazyroar'}
5) Using Data Class (Python 3.7+): In Python 3.7 and above the Data Class can be used to return a class with automatically added unique methods. The Data Class module has a decorator and functions for automatically adding generated special methods such as __init__() and __repr__() in the user-defined classes.
Python3
from dataclasses import dataclass@dataclassclass Book_list: name: str perunit_cost: float quantity_available: int = 0 # function to calculate total cost def total_cost(self) -> float: return self.perunit_cost * self.quantity_available book = Book_list("Introduction to programming.", 300, 3)x = book.total_cost()# print the total cost# of the bookprint(x)# print book detailsprint(book)# 900Book_list(name='Python programming.', perunit_cost=200, quantity_available=3) |
900 Book_list(name='Introduction to programming.', perunit_cost=300, quantity_available=3)
6. Using ‘yield’
One alternative approach for returning multiple values from a function in Python is to use the yield keyword in a generator function. A generator function is a special type of function that returns an iterator object, which generates a sequence of values on the fly, one value at a time.
To return multiple values from a generator function, you can use the yield keyword to yield each value in turn. The generator function will then pause execution until the next value is requested, at which point it will resume execution and yield the next value. This process continues until the generator function completes execution or encounters a return statement.
Here is an example of how this can be done:
Python3
def get_values(): yield 42 yield 'hello' yield [1, 2, 3]# Test coderesult = get_values()print(next(result)) # should print 42print(next(result)) # should print 'hello'print(next(result)) # should print [1, 2, 3] |
42 hello [1, 2, 3]
Time complexity: O(1) because it only performs a constant number of operations (yields) regardless of the size of the input.
Auxiliary space: O(1) because it only stores a constant number of variables (yielded values) in memory at any given time.
Reference: http://stackoverflow.com/questions/354883/how-do-you-return-multiple-values-in-python This article is contributed by Shubham Agrawal. If you like Lazyroar and would like to contribute, you can also write an article and mail your article to review-team@geeksforgeeks.org. See your article appearing on the Lazyroar main page and help other Geeks. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above
