<p>I used <a href="http://www.biostars.org/post/show/2822/extracting-multiple-fasta-sequences-at-a-time-from-a-file-containing-many-sequences/#2823">this piece of biopython codes</a> written by <a href="http://www.biostars.org/user/profile/216/">Eric Normandeau</a> to parse several sequences from a Fasta file.  The codes worked nicely. I would like to have my parsed output from this format </p>

<pre><code>&gt;DR179241 similar to UniRef100_A5HIY3 Cluster: Thaumatin-like protein; n=1; ...... ATAATCTTTAGATCAGTCATCAATCTCAACAGTATCGCTTTCAATTCTCTTTCATATTGC ATGGAAGTGTGTAAATACAATTAGGGCATTCATTGAGTTGACTTCATTTAAGCGCT......
</code></pre>

<p>exactly like this format:</p>

<pre><code>&gt;DR179241
ATAATCTTTAGATCAGTCATCAATCTCAACAGTATCGCTTTCAATTCTCTTTCATATTGC
ATGGAAGTGTGTAAATACAATTAGGGCATTCATTGAGTTGACTTCATTTAAGCGCT......
</code></pre>

<p>Could anyone kindly please light me for example how to modify <a href="http://www.biostars.org/post/show/2822/extracting-multiple-fasta-sequences-at-a-time-from-a-file-containing-many-sequences/#2823">this piece of biopython codes</a> written by <a href="http://www.biostars.org/user/profile/216/">Eric Normandeau</a> in order to suit my purpose? </p>

<p>Thank you very much and have a nice day.</p>

How about this (untested):

    #!/usr/bin/env python
    import sys
    from Bio import SeqIO
    
    fasta_file = sys.argv[1]  # Input fasta file
    result_file = sys.argv[2] # Output fasta file
    
    def modified(records):
        for record in records:
            #Clear the description
            record.description=""
            yield record
    
    records = modified(SeqIO.parse(fasta_file),"fasta")
    count = SeqIO.write(records, result_file, "fasta")
    print "Converted %i records" % count

This used a generator function to modify the records (memory efficient - you should avoid loading everything into memory). The key point for your request was to set the description to an empty string.