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.
# A Python program to return multiple
# values from a method using class
class Test:
def __init__(self):
self.str = "prutor"
self.x = 20
# 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:
prutor
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.
# A Python program to return multiple
# values from a method using tuple
# This function returns a tuple
def fun():
str = "prutor"
x = 20
return str, x; # Return tuple, we could also
# write (str, x)
# Driver code to test above method
str, x = fun() # Assign returned tuple
print(str)
print(x)
Output:
prutor
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.
# A Python program to return multiple
# values from a method using list
# This function returns a list
def fun():
str = "prutor"
x = 20
return [str, x];
# Driver code to test above method
list = fun()
print(list)
Output:
['prutor', 20]
4) Using a Dictionary: A Dictionary is similar to hash or map in other languages. See this for details of dictionary.
# A Python program to return multiple
# values from a method using dictionary
# This function returns a dictionary
def fun():
d = dict();
d['str'] = "prutor.ai"
d['x'] = 20
return d
# Driver code to test above method
d = fun()
print(d)
Output:
{'x': 20, 'str': 'prutor.ai'}
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.
from dataclasses import dataclass
@dataclass
class 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 book
print(x)
# print book details
print(book)
# 900
Book_list(name='Python programming.',
perunit_cost=200,
quantity_available=3)
Output:
900
Book_list(name='Introduction to programming.', perunit_cost=300, quantity_available=3)
Book_list(name='Python programming.', perunit_cost=200, quantity_available=3)