# List indexing

**URL:** <https://mworks.discourse.group/t/list-indexing/103>\
**Category:** Support\
**Created:** [September 9, 2021, 9:23am UTC](https://mworks.discourse.group/t/list-indexing/103 "2021-09-09T09:23:47Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\
**Post date:** [September 9, 2021, 9:23am UTC](https://mworks.discourse.group/t/list-indexing/103/1 "2021-09-09T09:23:47Z")

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Hi Chris,

How do I extract parts of a list? I realise that I can index single values from a list variable and use a while loop for operations, however, this seems computationally expensive. Is there a quick way to flexibly extract several entries from a list (similar to Matlab/Python syntax)?

var[0:n]  
var[n:m]  
var[n:end]

Also, is there a built-in feature to sum or average lists?

Cheers  
Felix

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**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\
**Post date:** [September 9, 2021, 9:01pm UTC](https://mworks.discourse.group/t/list-indexing/103/2 "2021-09-09T21:01:16Z")

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Hi Felix,

> How do I extract parts of a list? I realise that I can index single values from a list variable and use a while loop for operations, however, this seems computationally expensive. Is there a quick way to flexibly extract several entries from a list (similar to Matlab/Python syntax)?

Unfortunately, no – MWorks doesn’t support this. As a workaround, you could perform complex list manipulation in Python (via [run\_python\_file](https://mworks.github.io/documentation/latest/components/run_python_file.html), [run\_python\_string](https://mworks.github.io/documentation/latest/components/run_python_string.html), or the `py_eval` [function](https://mworks.github.io/documentation/latest/expressions/index.html#other)).

> Also, is there a built-in feature to sum or average lists?

No, but you could use Python for this, too.

Cheers,  
Chris

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**Author:** ![cstawarz](https://yyz1.discourse-cdn.com/flex031/user_avatar/mworks.discourse.group/cstawarz/32/3_2.png) [@cstawarz](https://mworks.discourse.group/u/cstawarz)\
**Post date:** [July 19, 2022, 7:01pm UTC](https://mworks.discourse.group/t/list-indexing/103/3 "2022-07-19T19:01:18Z")

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Closed on July 19, 2022, 7:01pm UTC