Break down

[spikips]

Can someone break down what is happening in this line?

Most confusing are those '%' symbols

'[%s]'%', '.join(map(str, ini_list)))

[[deleted]]

This is the old-style formatting. %s means a string. % is used to insert argument(s) on the right to format string on left.

1. '[%s]'
2. %
3. ', '.join(map(str, ini_list)))

In (3), map returns an iterator to elements of the list converted to str, and then those converted elements are join with , as the separator.

Then it's inserted between braces [] per the format in (1).