[Ethereum] How to obtain the public key (using web3)

You could try this library it works perfectly. https://github.com/LimelabsTech/eth-ecies

1. start ganache-cli with --acctKeys ganache-accounts.json parameter it will save all the data about accounts/keys

then use this script to extract public key :

#!/usr/bin/env python
import json
from pprint import pprint
import sys
file = sys.argv[1]
print file
json_data=open(file).read()
data = json.loads(json_data)
for a in data['addresses']:
    pubkeyArray=data['addresses'][a]['publicKey']['data']
    pubkey=""
    for pbk in pubkeyArray:
        pubkey = "%s%02x" % (pubkey,pbk)
    print "Address:%s" % a
    print "Public Key:0x%s" % pubkey 
    print "Private Key:0x%s" % data['private_keys'][a]

3. pass file name ganache-accounts.json to the script

4. it will produce output as follows :

./scripts/ganache-keys.py ./keystore/ganache-accounts.json 
./keystore/ganache-accounts.json
Address:0xb32613b32fd6f358259194c0a34e689e7eb9d88c
Public Key:0xf93e5a7cbd7b76cb3e2c1b362039397fbba00a0cbea1eccdf00e0e1e64d575411ae32bc6daf297aba31707fea7f84f20adb82c325fc33d347b54cf5fcd2bd71a
Private Key:0x30963a4383bfb78f0ecf290b1f3879a9c70903481e865f9e5d2df66ced64395d
Address:0x7c06350cb8640a113a618004a828d3411a4f32d3
Public Key:0xdcaa05bb5a82e0d1675d7f9b12b4d1948122500fc35ca7dee2edc99f2a3af2c5d6498f80dfbc0ab7c624793919aee8e4651adeefa7951c96438cad7838fbb9ea
Private Key:0x5641128d7d895f185d91fa2b83dffe646eede097d1a85c3247debc2b75219d92