Short answer, it depends on if the snake that is an example of a dominant mutation type is heterozygous or homozygous for the mutant gene. Hets have a 50% chance of passing the mutant gene to each offspring and homozygous animals pass it to 100% of their offspring.

The long answer:

I find working with genotypes to be the easy way to figure this stuff out.

The genotype heterozygous means having an unmatched pair of whatever gene you are talking about (example one spider mutant gene and one normal for spider gene). When a heterozygous python reproduces the egg has a 50/50 chance as to which copy of that gene it got from that parent. It doesn't mater if the mutation type of that gene is recessive, co-dominant, or dominant; a heterozygous parent has two different copies and randomly picks one to pass on to each egg.

Remember that the hatchling gets one copy of each gene from each parent. So, as long as you understand the parent's genotypes you should be able to figure out the possible combinations of a given gene the hatchling can end up with. However, there is a lot of confusion as to the genotype of dominant type (either co-dominant or completely dominant) potential parents. Because most snake people learned about recessive mutations first (most of the early known mutations where recessive), many tend to think that heterozygous only applies to normal looking gene carriers because that's the way it works out with recessive type mutations. Heterozygous really means having an unmatched pair of genes and pastels, mojaves, and spiders are hets with one normal and one mutant copy of the respective genes just like het albinos and het ghosts. For example, since a lesser has one copy of the lesser mutant gene and one normal copy of that gene it is a het and has a 50/50 chance of giving the lesser copy of the gene to each of its offspring.

Now where the mutation type comes in is in determining what the hatchling will look like relative to its genotype. With co-dominant mutation types the hets show their mutation but the homozygous genotypes are a different mutation (usually more extreme). In theory there could be a completely dominant mutation where the heterozygous and homozygous mutant animals look the same. I'm not really up on boas but read somewhere that perhaps hypo would be an example of this. There are several ball python mutations that could be completely dominant but I don't think any have been proven by producing a confirmed homozygous version that looks and acts the same as the heterozygous mutant.