# Multiply each element in a list by a number in Python Last updated: Jul 9, 2022 Photo from Unsplash

## Multiply each element in a list by a number in Python#

To multiply each element in a list by a number:

1. Use a list comprehension to iterate over the list.
2. On each iteration, multiply the current element by the number.
3. The new list will contain the multiplication results.
main.py
```Copied!```my_list = [2, 4, 6]

result = [item * 10 for item in my_list]

print(result)  # 👉️ [20, 40, 60]
``````

We used a list comprehension to iterate over the list and multiplied each list item by `10`.

List comprehensions are used to perform some operation for every element, or select a subset of elements that meet a condition.

On each iteration, we multiply the current list item by the specified number and return the result.

Alternatively, you can use a simple `for` loop.

To multiply each element in a list by a number:

1. Declare a new variable that stores an empty list.
2. Use a `for` loop to iterate over the original list.
3. On each iteration, multiply the current list item by the number.
4. Append the result to the new list.
main.py
```Copied!```my_list = [2, 4, 6]

result = []

for item in my_list:
result.append(item * 10)

print(result)
``````

The `for` loop works in a very similar way to the list comprehension, but instead of returning the list items directly, we append them to a new list.

You can also use the `map()` function to multiply each element in a list.

main.py
```Copied!```my_list = [2, 4, 6]

result = list(map(lambda item: item * 10, my_list))

print(result)  # 👉️ [20, 40, 60]
``````

The map() function takes a function and an iterable as arguments and calls the function with each item of the iterable.

The lambda function we passed to `map` gets called with each item in the list, multiplies the item by `10` and returns the result.

The last step is to use the `list()` class to convert the `map` object to a `list`.

If you work with numpy arrays, you can directly use the multiplication operator on the array to multiply each of its elements by a number.

main.py
```Copied!```import numpy as np

arr = np.array([2, 4, 6])

result = arr * 10

print(result)  # 👉️ [20 40 60]
``````
Multiplying a numpy array by a number effectively multiplies each element in the array by the specified number.

Note that this only works with numpy arrays. If you multiply a python list by a number, it gets repeated N times.

main.py
```Copied!```print([2, 4, 6] * 2) # 👉️ [2, 4, 6, 2, 4, 6]
``````

Multiplying a Python list by N, returns a new list containing the elements of the original list repeated N times.

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