Of course it will affect the price. Miners will have less bitcoin to sell, so by the economic law of supply and demand, it will in theory, increase the price. As the supply is now lower
Good explanation aside from that when that time comes next will be the time that all crypto believer awaits for because all of the coins will increase its price not only bitcoin.
The price will rise because of people logical expectations, 2020 is so close this year is time to buy bitcoin. But usually the price will rise before halving happen and people start to sell it again a few days before halving, we should keep an eye on the price chart a week before halving.