# Passing list of archives as input to plugin

**URL:** https://forum.qiime2.org/t/passing-list-of-archives-as-input-to-plugin/25048
**Category:** Developer Discussion
**Created:** [December 18, 2022, 3:18am UTC](https://forum.qiime2.org/t/passing-list-of-archives-as-input-to-plugin/25048 "2022-12-18T03:18:42Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![mroper](https://forum.qiime2.org/letter_avatar_proxy/v4/letter/m/cc9497/32.png) [@mroper](https://forum.qiime2.org/u/mroper)
#### Post date: [December 18, 2022, 3:18am UTC](https://forum.qiime2.org/t/passing-list-of-archives-as-input-to-plugin/25048/1 "2022-12-18T03:18:42Z")

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Hi,

I am not sure whether or not this is the correct forum. If not, my apologies.

But I am developing a plugin and I would like to pass a list of archives as an input to a method. I can't seem to do that at the commandline. Writing --i-input-list for the commandline key and 1.qza, 2.qza for example input archives, I have tried  
--i-input-list 1.qza, 2.qza  
and  
--i-input-list 1.qza --i-input-list 2.qza  
and  
--i-input-list 1.qza,2.qza  
and  
--i-input-list 1.qza 2.qza.

All of which fail. The error for --i-input-list 1.qza --i-input-list 2.qza  
is  
" issubclass() arg 1 must be a class "

I am quite lost as I need to process a list of archive inputs in my plugin. Are you able to help?

Thank you!

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### Author: ![misialq](https://forum.qiime2.org/user_avatar/forum.qiime2.org/misialq/32/9053_2.png) [@misialq](https://forum.qiime2.org/u/misialq)
#### Post date: [January 5, 2023, 2:15pm UTC](https://forum.qiime2.org/t/passing-list-of-archives-as-input-to-plugin/25048/3 "2023-01-05T14:15:41Z")

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Hey @mroper,

Could you please share how you define the Python function that is linked to the action you mentioned above? More specifically, how do you annotate the function input types? Your input for the `input_list` argument should not be annotated as a list of whatever you expect the user to provide but rather you should annotate it directly with the type of a single artifact.

Cheers,  
Michal

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### Author: ![mroper](https://forum.qiime2.org/letter_avatar_proxy/v4/letter/m/cc9497/32.png) [@mroper](https://forum.qiime2.org/u/mroper)
#### Post date: [January 6, 2023, 10:31am UTC](https://forum.qiime2.org/t/passing-list-of-archives-as-input-to-plugin/25048/4 "2023-01-06T10:31:46Z")

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Hi Michal,

Thanks for your reply. Are there any examples of this available online?

Thank you,  
Michael

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### Author: ![gregcaporaso](https://forum.qiime2.org/user_avatar/forum.qiime2.org/gregcaporaso/32/17769_2.png) [@gregcaporaso](https://forum.qiime2.org/u/gregcaporaso)
#### Post date: [January 10, 2023, 7:12pm UTC](https://forum.qiime2.org/t/passing-list-of-archives-as-input-to-plugin/25048/5 "2023-01-10T19:12:05Z")

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Hi @mroper,  
`qiime feature-table merge-seqs` is an example of this being done.

You can find the action registration [here](https://github.com/qiime2/q2-feature-table/blob/f01598e51815fd4ea25e8812c2c29eaef912bd4d/q2_feature_table/plugin_setup.py#L214) and the underlying Python function [here](https://github.com/qiime2/q2-feature-table/blob/f01598e51815fd4ea25e8812c2c29eaef912bd4d/q2_feature_table/_merge.py#L68). You can then see how this is used [here](https://docs.qiime2.org/2022.11/tutorials/fmt/#merging-denoised-data). Let us know if you need more help after seeing this example.