# Python – Multiply all cross list element pairs

• Last Updated : 06 Mar, 2020

Sometimes, while working with Python list, we can have a problem in which we need to perform multiplication of each element of list with other list. This can have application in both web development and day-day programming. Lets discuss certain ways in which this task can be performed.

Method #1 : Using list comprehension
This is the most straight forward method to perform this task. In this, we iterate the both the list and perform multiplication of each element with other and store result in new list.

 `# Python3 code to demonstrate ``# Multiply all cross list element pairs``# using list comprehension`` ` `# Initializing lists``test_list1 ``=` `[``4``, ``5``, ``6``]``test_list2 ``=` `[``6``, ``4``, ``2``]`` ` `# printing original lists``print``(``"The original list 1 is : "` `+` `str``(test_list1))``print``(``"The original list 2 is : "` `+` `str``(test_list2))`` ` `# Multiply all cross list element pairs``# using list comprehension``res ``=` `[i ``*` `j ``for` `j ``in` `test_list1 ``for` `i ``in` `test_list2]``             ` `# printing result ``print` `(``"The multiplication list is : "` `+` `str``(res))`
Output :
```The original list 1 is : [4, 5, 6]
The original list 2 is : [6, 4, 2]
The multiplication list is : [24, 16, 8, 30, 20, 10, 36, 24, 12]
```

Method #2 : Using `product()`
This is another way in which this task can be performed. In this, we perform the task of multiplication using product().

 `# Python3 code to demonstrate ``# Multiply all cross list element pairs``# using product()``from` `itertools ``import` `product`` ` `# Initializing lists``test_list1 ``=` `[``4``, ``5``, ``6``]``test_list2 ``=` `[``6``, ``4``, ``2``]`` ` `# printing original lists``print``(``"The original list 1 is : "` `+` `str``(test_list1))``print``(``"The original list 2 is : "` `+` `str``(test_list2))`` ` `# Multiply all cross list element pairs``# using product()``res ``=` `[a ``*` `b ``for` `a, b ``in` `product(test_list1, test_list2)]``             ` `# printing result ``print` `(``"The multiplication list is : "` `+` `str``(res))`
Output :
```The original list 1 is : [4, 5, 6]
The original list 2 is : [6, 4, 2]
The multiplication list is : [24, 16, 8, 30, 20, 10, 36, 24, 12]
```

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