Get taxonomic name of the rank of your choice from taxonomy ID

taxid2taxonomic_name.py

import doctest
import xml.etree.ElementTree as ET

from Bio import Entrez

Entrez.email = "example@example.com"  # replace it with your actual email address

def get_taxonomic_name(taxid, rank):
    '''Return the taxonomic name of the specified rank for the given taxonomy ID.
    Make sure you give a string, not an int value as taxid or efetch throws an exception.
    
    >>> get_taxonomic_name("511145", "phylum")  # 511145 for Escherichia Coli
    'Proteobacteria'

    >>> get_taxonomic_name("511145", "species")
    'Escherichia coli'

    >>> get_taxonomic_name("1236", "phylum")  # 1236 for Gammaproteobacteria
    'Proteobacteria'

    It fails when the given taxonomy ID doesn't have the specified rank.
    >>> get_taxonomic_name("1236", "species")  # you can't do this!
    Traceback (most recent call last):
    ...
    AttributeError: 'NoneType' object has no attribute 'text'
    '''

    handle = Entrez.efetch(db="taxonomy", id=taxid)
    root = ET.fromstring(handle.read())
    return root.find(".//Taxon[Rank='{0}']/ScientificName".format(rank)).text