Well, I was asked about this topic by a friend from another forum, and directed here after my response (the friend was not Wes, though I do consider him one; and the forum was not Fauna, though that is usually where I play). I'll preface my comment with the statement that I have fairly limited experience with BPs, but I have successfully bred a few other python species (as well as some colubrids) - so I am not exactly a stranger to egg incubation.

The snippet that was posted from the Barkers' book about egg respiration is absolutely correct (and, therefore, I have often wondered about the logic behind people's desire to seal their egg containers, but that's just me). Python eggs, in general (and not including those from drier climates, like womas, that do less well in "normal', or 'standard" conditions) can tolerate varying amounts of moisture & humidity. For those of you that like to quote/reference the Barkers - very knowledgeable & helpful people, and good sources to reference, btw - you may have also seen commentary (I believe it was with reference to JCP eggs, but it is true for many other species as well) that consistency of the moisture content/humidity is more important than the level of moisture content/humidity. Eggs that are kept drier or wetter thoughout the incubation period still tend to survive - but when they get drier or wetter during various stages (in other words, when the humidity level or moisture content is changed along the way), it can be lethal to the eggs.

Yes, warmth & humidity can encourage mold/fungus growth, but I have found that to be most prevalent on eggs, or parts of eggs, that have been touched more...or, to a lesser degree, eggs that get dripped on a lot. In most cases, the mold does not affect what is going on inside the egg...and most breeders will say to leave the egg alone & see if it hatches (some will take various measures against the mold, some don't bother). As far as water dripping on the eggs - one of the most common things I have seen resulting from this is spotting. It sometimes looks as if the egg is thinner in the spotted areas (so maybe it does do something to the integrity of the surface), but other times it is simply discolored. For what it's worth, my feeling is that if you have a lot of water dripping on your eggs, something should probably be changed - whether it be with the incubation process & setup, or your techniques (ie how you remove the lid).

As for the question about whether excess moisture will harm the eggs - it really depends on how much moisture you're talking about...with a good setup, and fairly consistent conditions, getting dripped on a couple of times is not going to kill them. If you are opening the egg container frequently, and more than a few drops fall on certain eggs every time, well, the results might not be so good.

To the person that commented about a bowl over the incubation container - a round or curved top, was considered an almost ideal situation for exactly the reason you described...namely that the water would trickle down the sides, as opposed to dripping on the eggs. (I suspect that it isn't more widely utilized because of the impact on space - taller containers & decreased stacking capability)