The python return statement is used to return values from the function. We can use the return statement in a function only. It can’t be used outside of a Python function.
Python Function without return statement
Every function in Python returns something. If the function doesn’t have any return statement, then it returns None.
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def print_something(s): print('Printing::', s) output = print_something('Hi') print(f'A function without return statement returns {output}') |
Output:
Python Function Without Return Statement
Python Return Statement Example
We can perform some operation in a function and return the result to the caller using the return statement.
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def add(x, y): result = x + y return result output = add(5, 4) print(f'Output of add(5, 4) function is {output}') |
Output:
Python Return Example
Python return statement with expression
We can have expressions also in the return statement. In that case, the expression is evaluated and the result is returned.
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def add(x, y): return x + y output = add(5, 4) print(f'Output of add(5, 4) function is {output}') |
Output:
Python Return Statement With Expression
Python return boolean
Let’s look at an example where we will return the boolean value of the argument of a function. We will use bool() function to get the boolean value of the object.
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def bool_value(x): return bool(x) print(f'Boolean value returned by bool_value(False) is {bool_value(False)}') print(f'Boolean value returned by bool_value(True) is {bool_value(True)}') print(f'Boolean value returned by bool_value("Python") is {bool_value("Python")}') |
Output:
Python Return Boolean
Python return string
Let’s look at an example where our function will return the string representation of the argument. We can use the str() function to get the string representation of an object.
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def str_value(s): return str(s) print(f'String value returned by str_value(False) is {str_value(False)}') print(f'String value returned by str_value(True) is {str_value(True)}') print(f'String value returned by str_value(10) is {str_value(10)}') |
Output:
Python Return String
Python return tuple
Sometimes we want to convert a number of variables into a tuple. Let’s see how to write a function to return a tuple from a variable number of arguments.
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def create_tuple(*args): my_list = [] for arg in args: my_list.append(arg * 10) return tuple(my_list) t = create_tuple(1, 2, 3) print(f'Tuple returned by create_tuple(1,2,3) is {t}') |
Output:
Python Function Return Tuple
Further Reading: Python *args and **kwargs
Python function returning another function
We can return a function also from the return statement. This is similar to Currying, which is the technique of translating the evaluation of a function that takes multiple arguments into evaluating a sequence of functions, each with a single argument.
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def get_cuboid_volume(h): def volume(l, b): return l * b * h return volume volume_height_10 = get_cuboid_volume(10) cuboid_volume = volume_height_10(5, 4) print(f'Cuboid(5, 4, 10) volume is {cuboid_volume}') cuboid_volume = volume_height_10(2, 4) print(f'Cuboid(2, 4, 10) volume is {cuboid_volume}') |
Output:
Python Return Function
Python function returning outer function
We can also return a function that is defined outside of the function with return statement.
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def outer(x): return x * 10 def my_func(): return outer output_function = my_func() print(type(output_function)) output = output_function(5) print(f'Output is {output}') |
Output:
Python Function Return Outer Function
Python return multiple values
If you want to return multiple values from a function, you can return tuple, list, or dictionary object as per your requirement.
However, if you have to return a huge number of values then using sequence is too much resource hogging operation. We can use yield, in this case, to return multiple values one by one.
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def multiply_by_five(*args): for arg in args: yield arg * 5 a = multiply_by_five(4, 5, 6, 8) print(a) # showing the values for i in a: print(i) |
Output:
Python Return vs Yield
Summary
The python return statement is used to return the output from a function. We learned that we can also return a function from another function. Also, expressions are evaluated and then the result is returned from the function.