per_page in woocommerce product by id shortcode ,

This shortcode does not use pagination so this isn’t possible,

But if this option is also available it will be more use full .Could you please tell how the default product structure in the product loop ?. Because currently it is mixed up in many pages like loop-end.php,loop-start.php etc

I need to manually loop the products through while loop ,that’s why iam asking the loop structure .

You don’t need to use our loop structure; you can output them however you want.

Example loop https://github.com/woothemes/woocommerce/blob/58b185e7a6dfa0359ca86f6190854eb536409422/includes/class-wc-shortcodes.php#L84-L115

Thank you very much .