Reading from a file

[RodAG]

I'm trying to get data from a txt file, still I don't know how to do it. The data is in fasta format (a format used in molecular biology to store protein/DNA sequences) whis is very simple:

>Header1
Sequence1

>Header2
Sequence2
.
.
.
>HeaderN
SequenceN

The ">" is always present and denotes an identifier line (in which we usually write the name/id of the sequence below). The line or lines following the header are the proper sequence, which have different lenghts.

So, my question is which instructions to use so I can read the file and copy all the sequences, each one in a list for itself.
Any ideas? Thanks in advance.

[bvdet]

The following code will read a text file and create a dictionary of headers and sequences.

f = open("fasta1.txt")
dd = {}
current_header = False
for line in f:
    if line.startswith(">"):
        current_header = line[1:].strip()
    elif current_header:
        dd.setdefault(current_header, []).append(line.strip())
f.close()

It saves the sequences in a list in case the sequence spans over multiple lines.