I have a bitcoin private key and know that it can output a segwit addresses of bech32 bc1... and p2sh 3... formats. How can this be done easily?
Load up electrum 3.1.1+ and enable the "console" and in the console do the following to output the addresses you need by providing your private key:
bech32 format bc1...:
p2sh format 3...:
you just need to prefix your private key with p2wpkh or p2wpkh-p2sh to get one of them.