Change last record separator with awk

Question

I have an input file as below:

apple 6
banana 7
goat 8

and I need output as

{6,apple},
{7,banana},
{8,goat}

However, when I run the awk as below, it is printing extra last comma (,). How to avoid that last comma ?

awk '{print "{"$2","$1"},"}' data
{6,apple},
{7,banana},
{8,goat},

Update:

Actually, I needed output like this

{6,apple},
{7,banana},
{8,goat}
] 

and when I run

awk '{print "{"$2","$1"},"}' END {print "\t\t]\n}' data

it gives me

{6,apple},
{7,banana},
{8,goat}, 
] 

I don't need the last comma... How to it avoid in this case?

Answer 1

Using printf and delayed printf of the comma:

$ awk '{printf "%s{%s,%s}",(NR==1?"":"," ORS),$2,$1} END{print ORS "]"}' file
{6,apple},
{7,banana},
{8,goat}
]

Answer 2

How about piping it to sed with the following command line ?

awk ... | sed '$ s/,$//'