The setLog transaction has not yet been mined by the time the the getLog call is made.
I've cleaned up your code a bit for readability, and turned your while loop into a function with a timeout. Ive also taken the liberty of making updates to use the web3.py v4 pre-release.
the web3.py pre-release (allong with eth_tester) can be installed with:
$ pip install --pre web3[tester]
import json
import time
from web3 import Web3
from web3.providers.eth_tester import EthereumTesterProvider
from solc import compile_source
from web3.contract import ConciseContract
import time
contract_source_code = '''
pragma solidity ^0.4.11;
contract contract_log {
string name;
string time;
string product;
function contract_log(){
name='kk';
}
function setLog(string a, string b, string c) public {
name = a;
time = b;
product = c;
}
function getLog() constant returns (string, string, string) {
return (name, time, product);
}
}
'''
def wait_on_tx_receipt(tx_hash):
start_time = time.time()
while True:
if start_time + 60 < time.time():
raise TimeoutError("Timeout occurred waiting for tx receipt")
if w3.eth.getTransactionReceipt(tx_hash):
return w3.eth.getTransactionReceipt(tx_hash)
compiled_sol = compile_source(contract_source_code) # Compiled source code
contract_interface = compiled_sol['<stdin>:contract_log']
w3 = Web3(EthereumTesterProvider())
contract = w3.eth.contract(abi=contract_interface['abi'], bytecode=contract_interface['bin'])
deploy_tx_hash = contract.deploy(transaction={'from': w3.eth.coinbase, 'gas':500000})
contract_address = wait_on_tx_receipt(deploy_tx_hash).contractAddress
contract_instance = w3.eth.contract(abi=contract_interface['abi'], address=contract_address)
tx_hash = contract_instance.functions.setLog(
'tlatk',
'12',
'product').transact({'from':w3.eth.coinbase,'gas':500000})
wait_on_tx_receipt(tx_hash)
print(contract_instance.functions.getLog().call())