# Multiply all Numbers in Python List

How to multiply all numbers in the Python list? You can use the multiplication operator (*) is indeed used for multiplying two numbers together. It can be used with numbers of any type, including integers, floating-point numbers, and complex numbers. You can multiply all numbers in the list using many ways, for example, by using the `traversal`, `numpy.prod()`, `math.prod()`, lambda & reduce(), `mul()`, traversal by index, reduce() & mul(), `itertools.accumulate`, and `recursive` functions. In this article, I will explain how to multiply all numbers in the list by using all these methods with examples.

## 1. Quick Examples of Multiplying all Numbers in the List

If you are in a hurry, below are some quick examples of multiplying all numbers in the list.

``````
# Quick examples of multiply all numbers in the list

# Initialize the list
mylist = [2, 3, 4, 5]

# Example 1: Multiply all elements in a list
# Using the traversal
def multiply_list_numbers(mylist):
result = 1
for x in mylist:
result = result * x
return result
result = multiply_list_numbers(mylist)

# Example 2: Multiply all elements in the list
# Using numpy.prod()
result = np.prod(mylist)

# Example 3: Multiply all elements in the list
# Using math.prod
mylist = [2, 3, 4, 5]
result = math.prod(mylist)

# Example 4: Using lambda & reduce() function
result = reduce((lambda x, y: x * y), mylist)

# Example 5: Multiply all elements in the list
# Using mul() function of operator module
result = 1
for i in mylist:
result = mul(i, result)

# Example 6: Using traversal by index
def multiplyList(mylist):
result = 1
for i in range(0,len(mylist)):
result = result * mylist[i]
return result
result = multiplyList(mylist)

# Example 7: Using itertools.accumulate
result = list(accumulate(mylist, (lambda x, y: x * y)))

# Example 8: Using reduce() and the mul() function
result = reduce(mul, mylist)

# Example 9: Using the recursive function
def product_recursive(numbers):
if not numbers:
return 1
return numbers * product_recursive(numbers[1:])
result = product_recursive(mylist)
``````

## 2. Multiply all Elements in a List Using Traversal

To perform multiplication over the list of elements use `traversal`. You can use a simple loop to iterate over the list and multiply each element with an initial value. For example, to multiply all elements `mylist` using the traversal you can initialize the `result` variable to `1` and iterate over each element in `mylist`, then multiply each element with the current value of the `result`. Finally, it returns the `result`. This means that `2*3*4*5` equals `120`, which is the expected result.

``````
# Multiply all elements in a list
# Using traversal
def multiply_list_numbers(mylist):
result = 1
for x in mylist:
result = result * x
return result

# Initialize list
mylist = [2, 3, 4, 5]
result = multiply_list_numbers(mylist)
print("Multiplication of given list:", result)
``````

Yields below output.

## 3. Multiply all Elements in the List Using numpy.prod()

To calculate multiplication over the elements in the `mylist` using `numpy.prod()`. This is a part of the NumPy module, a library of Python that is used to calculate scientific calculations. Before going to use any functions of numpy module we need to import numpy module. First, initialize the `mylist` variable, and then use `np.prod(mylist)` to calculate the product of all elements in the list.

This means that `2*3*4*5` equals `120`, which is the expected result. Using `numpy.prod()` can be a convenient and efficient way to multiply all elements in a list.

``````
import numpy as np
# Initialize the list
mylist = [2, 3, 4, 5]

# Multiply all elements in the list
# Using numpy.prod()
result = np.prod(mylist)
print("Multiplication of given list:", result)
``````

Yields the same output as above.

## 4. Multiply all Elements in the List Using math.prod()

You can also use `math.prod()` to multiply all elements in the `mylist`. First, you can import the math module and initialize the `mylist `variable, and then use `math.prod(mylist)` to calculate the product of all elements in the list.

Note – the `math.prod()` function is available in Python `3.8` or later versions and provides a convenient way to multiply all elements in a list.

``````
import math
# Initialize list
mylist = [2, 3, 4, 5]

# Multiply all elements in the list
# Using math.prod
result = math.prod(mylist)
print("Multiplication of given list:", result)
``````

Yields the same output as above.

## 5. Using Lambda & reduce() Function

You can also use the reduce() function that has been moved from the `functools` module. So, you can use the `reduce()` function directly without importing it from `functools`. For example, the `reduce() `function is used along with a lambda function to multiply all elements in the `mylist`. The `lambda` function takes two arguments `x` and `y` and performs the multiplication operation `x * y`. The `reduce()` function applies this `lambda` function to pairs of elements in the list, reducing them to a single result.

``````
from functools import reduce

# Initialize list
mylist = [2, 3, 4, 5]

# Using lambda & reduce() function
result = reduce((lambda x, y: x * y), mylist)
print("Multiplication of given list:", result)
``````

Yields the same output as above.

## 6. Using mul() Function of Operator Module

Alternatively, you can use the `mul()` function from the operator module to multiply all elements in the `mylist`. First, initialize the `mylist` variable and set the initial value of `result` to `1`. And then iterate over each element in `mylist `and use the `mul()` function to multiply the current element with the current value of `result`.

``````
from operator import*
# Initialize list
mylist = [2, 3, 4, 5]

# Multiply all elements in list
# Using mul() function of operator module
result = 1
for i in mylist:
result = mul(i, result)
print("Multiplication of given list:", result)
``````

Yields the same output as above.

## 7. Multiply all Elements in the List Using Traversal by Index

To multiply all elements in the `mylist` use traversal by index. First, initialize the mylist variable, and set the initial value `result` to `1`, and then use a for loop to iterate over the indices of the list. You can multiply each element at the index `i` with the current value of `result` and update the result variable. Using traversal by index allows you to access each element of the list using its index and perform the multiplication operation.

``````
# Using traversal by index
def multiplyList(mylist):
result = 1
for i in range(0,len(mylist)):
result = result * mylist[i]
return result

# Initialize list
mylist = [2, 3, 4, 5]
result = multiplyList(mylist)
print("Multiplication of given list:", result)
``````

Yields the same output as above.

## 8. Multiply all Elements in the List Using itertools.accumulate

To perform multiplication over all elements in the `mylist` use `itertools.accumulate()`. First, import the `accumulate()` function from the `itertools` module. This function takes the `mylist` and `lambda` function `(lambda x, y: x * y)` as arguments. This lambda function performs the multiplication operation on two elements `x` and `y`.

The `accumulate()` function returns an iterator that yields the accumulated results at each step. By converting the iterator to a list using list(), you can access the last element `result[-1]`, which represents the final product.

``````
from itertools import accumulate

# Initialize list
mylist = [2, 3, 4, 5]

# Multiply all elements in list
# Using itertools.accumulate
result = list(accumulate(mylist, (lambda x, y: x * y)))
print("After multiplying all elements in a list:", result[-1])
``````

Yields the same output as above.

## 9. Using reduce() and the mul() Function

Similarly, you can use reduce() and the `mul()` function from the operator module to multiply all elements `mylist`. First import `reduce()` from the `functools` module and `mul()` from the operator module. This `reduce()` function takes the mul() function and the `mylist` as arguments. The `mul()` function performs the multiplication operation on two elements. Using `reduce()` and the `mul()` function provides an efficient way to multiply all elements in a list.

``````
from functools import reduce
from operator import mul

# Initialize list
mylist = [2, 3, 4, 5]

# Using reduce() and the mul() function
result = reduce(mul, mylist)
print("After multiplying all elements in a list:", result)
``````

Yields the same output as above.

## 10. Using the recursive Function

To multiply all elements in the `mylist` use a recursive function `product_recursive()`. The `product_recursive()` function takes a list of numbers as input. It checks if the list is empty, and if so, it returns 1 as the base case for the recursion. If the list is not empty, it recursively calls `product_recursive()` with the sublist starting from the second element, and multiplies it with the first element of the list.

``````
# Multiply all elements in the list
# Using the recursive function
def product_recursive(numbers):
if not numbers:
return 1
return numbers * product_recursive(numbers[1:])

# Initialize list
mylist = [2, 3, 4, 5]
result = product_recursive(mylist)
print("After multiplying all elements in a list:", result)
``````

Yields the same output as above.

## Conclusion

In this article, I have explained Python multiplies all numbers in the list by using traversal, `numpy.prod()`, `math.prod()`, lambda & reduce(), `mul()`, traversal by index, `itertools.accumulate`, reduce() & mul(), and recursive functions. Also, learned how to use the math module and NumPy module to calculate products with examples.

Happy Learning !!

### Malli

Malli is an experienced technical writer with a passion for translating complex Python concepts into clear, concise, and user-friendly articles. Over the years, he has written hundreds of articles in Pandas, NumPy, Python, and takes pride in ability to bridge the gap between technical experts and end-users. 