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# Python | Convert String list to ascii values

• Difficulty Level : Expert
• Last Updated : 31 Jan, 2023

Sometimes, while working with Python, we can have a problem in which we need to convert String List to ascii values. This kind of problem can occur many times. Let’s discuss certain ways in which this task can be performed.

Method #1 : Using loop + ord() This problem can be solved using above functionalities. In this, we iterate the list and convert each character to it’s ascii number using ord().

## Python3

 `# Python3 code to demonstrate working of``# Convert String list to ascii values``# using loop + ord()` `# initialize list``test_list ``=` `[``'gfg'``, ``'is'``, ``'best'``]` `# printing original list``print``("The original ``list` `: " ``+` `str``(test_list))` `# Convert String list to ascii values``# using loop + ord()``res ``=` `[]``for` `ele ``in` `test_list:``    ``res.extend(``ord``(num) ``for` `num ``in` `ele)` `# printing result``print``("The ascii ``list` `is` `: " ``+` `str``(res))`

Output :

```The original list : ['gfg', 'is', 'best']
The ascii list is : [103, 102, 103, 105, 115, 98, 101, 115, 116]```

Time Complexity: O(N*N)

Auxiliary Space: O(N)

Method #2 : Using list comprehension + ord() This is yet another way to perform this task. This is just shorthand to above problem in which we compact the code using list comprehension using similar logic.

## Python3

 `# Python3 code to demonstrate working of``# Convert String list to ascii values``# using list comprehension + ord()` `# initialize list``test_list ``=` `[``'gfg'``, ``'is'``, ``'best'``]` `# printing original list``print``("The original ``list` `: " ``+` `str``(test_list))` `# Convert String list to ascii values``# using list comprehension + ord()``res ``=` `[``ord``(ele) ``for` `sub ``in` `test_list ``for` `ele ``in` `sub]` `# printing result``print``("The ascii ``list` `is` `: " ``+` `str``(res))`

Output :

```The original list : ['gfg', 'is', 'best']
The ascii list is : [103, 102, 103, 105, 115, 98, 101, 115, 116]```

Time Complexity: O(N*N)

Auxiliary Space: O(N)

Method#3: Using reduce() and map function + ord function: reduce is used to iterate over the list of string and Map function is used to convert the string to list of its ascii value by using ord as it’s function.

## Python3

 `# Python 3 code to convert``# string list to ascii value``# using reduce and map function``#importing reduce function``from` `functools ``import` `reduce` `# list of string``test_str ``=` `[``"gfg"``, ``"is"``, ``"best"``];` `# printing original list``print``(``"Original list is : "` `+` `str``(test_str))` `# using reduce and map to convert``# list of string to ascii value``k ``=` `reduce``(``lambda` `x,y 😡 ``+` `list``(``map``(``ord``, y)),test_str, [])``print``(``"The ascii list is : "``, ``str``(k))`

Output:

```Original list is : ['gfg', 'is', 'best']
The ascii list is :  [103, 102, 103, 105, 115, 98, 101, 115, 116]```

Time Complexity: O(N)

Auxiliary Space: O(N)

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