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# Python – Append given number with every element of the list

• Last Updated : 26 Nov, 2020

Given a list and a number, write a Python program to append the number with every element of the list.

Examples:

input = [1,2,3,4,5]

key = 5 (number to be appended)

output = [1,5,2,5,3,5,4,5,5,5]

The following are ways to achieve this functionality:

Method 1: Using for loop

## Python

 `input` `=` `[``1``, ``2``, ``3``, ``4``, ``5``]``key ``=` `7`` ` `result ``=` `[]``for` `ele ``in` `input``:``    ``result.append(ele)``    ``result.append(key)`` ` `print``(result)`

Output:

`[1, 7, 2, 7, 3, 7, 4, 7, 5, 7]`

Method 2: Using list comprehension and itertools.chain

## Python

 `import` `itertools`` ` `input` `=` `[``1``, ``2``, ``3``, ``4``, ``5``]``key ``=` `7`` ` `result ``=` `list``(itertools.chain(``*``[[ele, key] ``for` `ele ``in` `input``]))`` ` `print``(result)`

Output:

`[1, 7, 2, 7, 3, 7, 4, 7, 5, 7]`

Method 3: Using zip and for loop

## Python

 `input` `=` `[``1``, ``2``, ``3``, ``4``, ``5``]``key ``=` `7`` ` `result ``=` `[]``for` `x, y ``in` `zip``(``input``, [key]``*``len``(``input``)):``    ``result.extend([x, y])`` ` `print``(result)`

Output:

`[1, 7, 2, 7, 3, 7, 4, 7, 5, 7]`

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