# How to add all numbers in a list in Python

Hi everyone, today in this tutorial let us see **how to add all numbers in a list in Python**. Basically, we can add numbers in a list in many ways, like in other programming languages we can use * loops(for loop, while loop)*. We can also use

**lambda.**But in our tutorial let us see how to add elements in a list using * built-in function* and

*. This way of doing is better than using other methods. This is because slicing is an important technique in machine learning.*

**slicing**## How can you add all numbers in a list in Python

Let us now see how to add all numbers in a list using a built-in function. We use * sum()* which is a built-in function in Python programming language.

### sum()

The * sum() *is a built-in function as said earlier. This function will work only when

*numeric values*are given to it, this will not work when

*alphabets*are given to it or when numbers are given in the form of

*string*it will show errors. This function basically sums up the numbers that are given to this and return the sum of numbers given in it.

Now, let us see the code.

p=[2,3,5] print(sum(p))

**OUTPUT:**

10

Let us now see the usage of *for loop* in *sum()* function.

p=[2,3,5] print(sum(i for i in p))

**OUTPUT:**

10

You can also use the sum() function to add a constant value for the sum total of the list. The syntax of the sum() function is * sum(iterable, start). *So here, start means a value that can be summed up to the list and iterable means list, tuple, dict, etc.,

p=[2,3,5] print(sum(p,50))

**OUTPUT:**

60

Now, let us see how to add a list of numbers using the slicing method.

### Slicing

This slicing is an amazing feature given to us in Python language. This way of writing the code and analyzing the data plays a key role in Machine learning and Deep learning techniques.

Let us now have a look on our code.

y=[1,7,5,6,3] s=sum(y[0:len(y)]) print(s)

**OUTPUT:**

22

You may also read:

- How to print each item from a Python list?
- Python program to interchange first and last elements in a list

Thanks, this was super useful. i was having much trouble adding up a list.