Please note that visitors to Paris are likely to encounter localized congestion due to events surrounding the funeral of late French President Jacques Chirac.
Sunday his body will lie in state at the Invalides and there will be a national homage in his honor; Monday morning early his family will hold a funeral mass; then at noon there will be the big funeral mass at St Sulpice in the 6th, after which there will be a private family ceremony for the interment at Montparnasse cemetery.
In addition with some world leaders expected to attend, there are likely to be various jam-ups as their motorcades make their way around town; depending on the level of foreign visitor, sometimes you will encounter metro stations closed temporarily or some such.
I don’t think much of this will ruin any tourist’s visit except for people who had hoped/planned on visiting Invalides or St Sulpice over the next couple of days.
But just to be aware of as you are moving about town on Sunday and Monday.