Question about md5 hash

[Nicholas_Bokulich]

@hdeel

My question is does the md5 hash have some sort if meaning, i.e. is there a specific hash assigned based on the sequence or is it just a random generator that would give a different set of feature IDs for each rep-seqs file?

Yes, the md5sum will be "unique" for each unique sequence (i.e., a unique sequence will always have the same md5sum, but I say unique in scare quotes because there is an extremely small possibility that two text strings will have the same md5sum)

@hdeel

or to make a python script that will either make unique feature IDs that are consistent between each of the runs (or I could generate md5 hashes this way, as described in the other post).

A python script would be ideal — and something you could contribute as a method that others could use in QIIME 2! The bash script I wrote here will do the trick, but this issue has come up for QIIME 2 users a few times now so a formal QIIME 2 solution would be ideal. Please do write that script and submit a pull request to add it as a QIIME 2 method!

@hdeel

If I were to make a python script, which may be quicker, do you know if this would affect downstream analysis in any way?

It should not if features are being relabeled correctly.