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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def get_raw_blast(pdb_id, output_form='HTML', chain_id='A'):
    '''Look up full BLAST page for a given PDB ID

    get_blast() uses this function internally

    Parameters
    ----------

    pdb_id : string
        A 4 character string giving a pdb entry of interest

    chain_id : string
        A single character designating the chain ID of interest


    output_form : string
        TXT, HTML, or XML formatting of the outputs

    Returns
    -------

    out : OrderedDict
        An ordered dictionary object corresponding to bare xml

    '''

    url_root = 'http://www.rcsb.org/pdb/rest/getBlastPDB2?structureId='
    url = url_root + pdb_id + '&chainId='+ chain_id +'&outputFormat=' + output_form
    req = urllib.request.Request(url)
    f = urllib.request.urlopen(req)
    result = f.read()
    result = result.decode('unicode_escape')
    assert result

    return result