I have two text files that have similar formatting. The first (732KB):
>lib_1749;size=599;
TACGGAGGATGCGAGCGTTATCCGGATTTATTGGGTTTAAAGGGAGCGTAGGCGGACTATTAAGTCAGCTGTGAAAGTTTGCGGCTCAACCGTAAAATTGCTAGCGGTGAAATGCTTAGATATCACGAAGAACTCCGATTGCGAAGGCAGCTCACTAGACTGTCACTGACACTGATGCTCGAAAGTGTGGGTATCAAACA
--
>lib_2235;size=456;
TACGGAGGATCCGAGCGTTATCCGGATTTATTGGGTTTAAAGGGAGCGTAGGCGGACTATTAAGTCAGCTGTGAAAGTTTGCGGCTCAACCGTAAAATTGCTAGCGGTGAAATGCTTAGATATCACGAAGAACTCCGATTGCGAAGGCAGCTTACTGGACTGTAACTGACGTTGAGGCTCGAAAGCGTGGGGAGCAAACA
--
>lib_13686;size=69;
TACGTATGGAGCAAGCGTTATCCGGATTTACTGGGTGTAAAGGGAGTGTAGGTGGCCAGGCAAGTCAGAAGTGAAAGCCCGGGGCTCAACCCCGGGGCTGGTAGCGGTGAAATGCGTAGATATTAGGAGGAACACCAGTGGCGAAGGCGGCTTGCTGGACTGTAACTGACACTGAGGCTCGAAAGCGTGGGGAGCAAACA
--
The second (5.26GB):
>Stool268_1 HWI-ST155_0605:1:1101:1194:2070#CTGTCTCTCCTA
TACGGAGGATGCGAGCGTTATCCGGATTTACTGGGTTTAAAGGGAGCGCAGACGGGACGTTAAGTCAGCTGTGAAAGTTTGGGGCTCAACCCTAAAACTGCTAGCGGTGAAATGCTTAGATATCGGGAGGAACTCCGGTTGCGAAGGCAGCATACTGGACTGCAACTGACGCTGATGCTCGAAAGTGTGGGTATCAAACAGG
--
Note the key difference is the header for each entry (lib_1749 vs. Stool268_1). What I need is to create a mapping file between the headers of one file and the headers of the second using the sequence (e.g., TACGGAGGATGCGAGCGTTATCCGGAT...
) as a key.
Note as one final complication the mapping is not going to be 1-to-1 there will be multiple entries of the form Stool****** for each entry of lib****. This is because the length of the key in the first file was trimmed to have 200 characters but in the second file it can be longer.
For smaller files I would just do something like this in python but I often have trouble because these files are so big and cannot be read into memory at one time. Usually I try unix utilities but in this case I cannot think of how to accomplish this.
Thank you!