Fetch a DNA sequence from the UCSC Das web server

fetch-das.py

def dna_sequence_from_DAS(build: str, chrom: str, start: int, end: int) -> str:
    """
    Return the DNA sequence along an interval for a reference sequence build.

    Uses the DAS web server.

    Args:
        build: The UCSC genome build.
        chrom: The reference sequence name.
        start: The 1-based start locus.
        end: The inclusive end locus.

    Returns:
        seq: The DNA sequence in the specified interval of the genome build.

    """
    host = f'http://genome.ucsc.edu/cgi-bin/das/{build}/dna'
    response = requests.get(host, params={'segment': f'{chrom}:{start},{end}'})
    return ElementTree.fromstring(response.content).find('.//DNA').text.replace('\n', '')