Python Error

[subhabangalore at gmail.com]

Dear Group,

I was trying to convert the list to a set, with the following code:

set1=set(list1)

the code was running fine, but all on a sudden started to give the following error,

set1=set(list1)
TypeError: unhashable type: 'list'

please let me know how may I resolve.

And sometimes some good running program gives error all on a sudden with no parameter changed, how may I debug it?

Thanking You in Advance,

Regards,
Subhabrata Banerjee.