Python Function Types

In this lesson, We will examine the many functions in Python, including built-in, recursive, lambda, and user-defined functions, along with their syntax and examples. Also, we will learn about some of the python function’s lists, the advantages of using user-defined functions, and recommended best practices.

The Python Function Tutorial will now begin.

There are four categories into which we can divide functions:

  • Python Built-In Functions
  • Python User-Defined Functions
  • Python Recursion Function
  • Python Lambda Function

Python Built-in functions

Several features of the Python interpreter are available at all times. The functions whose functionality is predefined in Python are referred to as built-in functions in Python. You can find information on Python’s built-in functions on the reference page.

Python abs()

The abs() function in Python returns the absolute value of a number.

Python all()

The All() function in Python returns true when all elements in iterable are true.

Python any()

The any() function in python checks if any element of an Iterable is True

Python repr()

The repr() function in Python returns a printable representation of the object.

Python reversed()

The reversed() function in Python returns the reversed iterator of a sequence.

Python round()

The python round() function rounds a number to specified decimals.

Python set()

The python set() function constructs and returns a set.

Python setattr()

The python setattr() function sets the value of an attribute of an object.

Python slice()

The python slice() function returns a slice object.

Python sorted()

Python’s sorted() method uses the supplied iterable to produce a sorted list.

Python str()

The python str() function returns the string version of the object.

Python sum()

The python sum() function adds items of an Iterable.

Python super()

The python super() function returns a proxy object of the base class.

Python tuple()

The tuple() function in Python returns a tuple.

Python type()

The type() function in Python returns the type of the object.

Python __import__()

The import statement calls the python import function.

Python User-Defined Functions

User-defined functions are those that we define ourselves to carry out a particular purpose. We’ve already learned about how to define and call functions in Python.

Built-in functions are those that come pre-installed with Python. It is possible to refer to functions that are used that were created by others as library functions. User-defined functions include all additional functions that we create on our own. Therefore, to someone else, our user-defined function might be a library function.

Python User-Defined Function Benefits

  • User-defined functions in Python make comprehending, maintaining, and debugging programs easier by breaking them into manageable chunks. Suppose a program has repeated code. You can put codes in a function called to run when necessary.
  • Computer programmers working on huge projects can divide their workload by creating various functions.

Python Recursion Function

You will discover how to develop a recursive function in this lesson (a function that calls itself).

What Is Recursion Function?

The Latin verb recurrent, which means to hurry or hasten back, return, revert, or recur, is where the word “recursion” originates.
“The act of running back is recursion.”

A physical example would be to align two parallel mirrors to face one another. You can reflect any object in their path recursively.

The Benefits of Recursion

  • Code that uses recursive functions appears organized and beautiful.
  • Recursion allows for breaking a challenging assignment into smaller, more manageable issues.
  • Recursion makes it simpler to generate sequences than some nested iteration.

Negative Effects of Recursion

  • Recursion’s reasoning can be tricky to understand at times.
  • Recursive calls are time- and memory-intensive, making them costly (inefficient).
  • Debugging recursive functions is challenging.

Understand When to use Recursion

  • The majority of programming issues may be resolved without Recursion. In other words, Recursion is typically not required. A recursive approach would probably be cleaner and shorter if you were programming an algorithm to handle such a circumstance. In other words, a function calls itself. This advantage is that you can loop through the data to get a result.
  • Another notable example is the traversal of data structures that resemble trees. These structures are easily defined as recursive because they are nested. A recursive solution will be more elegant than a non-recursive one, making it easier to travel through nested structures.
A frequent idea in mathematics and computer programming is Recursion. Recursion may, under some circumstances, cause execution times to be longer. Note that memory use for recursive implementations is frequently higher than for non-recursive ones.

Recursion requires great attention on the developer’s part because writing a function that never ends or consumes excessive amounts of memory or processing resources is very simple. However, Recursion may be a very effective and elegant mathematical method for programming if appropriately used.

Recursion in Python

The Python interpreter constructs a new local namespace when you call a function to prevent names declared within a function from colliding with those defined elsewhere. Because the objects have different names and live in different namespaces, one function can call another even if they declare identical objects.

Here is an illustration of a recursive function that calculates an integer’s factorial.

The sum of all the integers from 1 to a certain number is factorial. For instance, 1*2*3*4*5 = 120 is the factorial of 5.


def facFunc(var):
    if var == 1:
        return 1
        rec_call = facFunc(var - 1)
        res = rec_call * var
        print (var, '*', rec_call, '=', res)
        return res

number = 5
print ('Result= The Factorial of', number, 'is', facFunc(number))


2 * 1 = 2
3 * 2 = 6
4 * 6 = 24
5 * 24 = 120
Result= The Factorial of 5 is 120

This function will call itself recursively by decreasing the number (facFunc(var-1) )when called with a positive integer. Until an integer equals one, each function multiplies it by the factorial of the number below it. When the number falls to 1, our Recursion comes to an end. Every recursive function needs a base condition to end the Recursion; otherwise, it will keep calling itself. The base condition is what we refer to as. The Python interpreter restricts the recursion depths to prevent infinite recursions that could lead to stack overflows.