Question about code writing '% i, callback'

[Terry Reedy]

On 11/30/2015 11:44 AM, fl wrote:

> I come across the following code snippet.

> for i in range(10):
>      def callback():
>          print "clicked button", i
>      UI.Button("button %s" % i, callback)

> http://effbot.org/zone/default-values.htm

Note that the above is an intentional example of common buggy code.  It 
is followed by a version that works, with 'i=i' added to the callback 
header.

-- 
Terry Jan Reedy