Parsing XMLs in Python safely

Suppose we want to find values of a specific field from a xml webpage. For example, let’s extract units of some of the attributes that are available in this item on ScienceBase. Here’s how we can achieve this using defusedxml and AsyncRetriever safely:

import async_retriever as ar
import defusedxml.ElementTree as ET
import pandas as pd

# A list of urls and payloads of the tagret XMLs
urls, kwds = zip(
    *[
        (
            "https://www.sciencebase.gov/catalog/file/get/57867b1be4b0e02680c14ff6",
            {"f": "__disk__e9/8b/ec/e98becc07c2de2b27396f1baefb29fa233b8f0f7"},
        ),
        (
            "https://www.sciencebase.gov/catalog/file/get/5785595ce4b0e02680bf2fd8",
            {"f": "__disk__e7/8b/7d/e78b7dbf4c31e60de6696697e62c04ee688a56d3"},
        ),
        (
            "https://www.sciencebase.gov/catalog/file/get/57dafd3ae4b090824ffc32f1",
            {"f": "__disk__9b/e6/04/9be604f55425b2691158260123a914cd0efae0da"},
        ),
        (
            "https://www.sciencebase.gov/catalog/file/get/573b5344e4b0dae0d5e3ad9c",
            {"f": "__disk__9f/5c/50/9f5c50b2f0da613b0969c574716d13b67903e274"},
        ),
        (
            "https://www.sciencebase.gov/catalog/file/get/57ffb392e4b0824b2d16f4c6",
            {"f": "__disk__dc/e8/d6/dce8d6f3b41e9ec33f9364a352e5e73055cfdc92"},
        ),
    ]
)

# Async retrieval
xmls = ar.retrieve(urls, "text", [{"params": p} for p in kwds])

# Parsing the results and converting to a Pandas dataframe
units = []
for xml in xmls:
    root = ET.fromstring(xml)
    for item in root.findall("./eainfo/detailed/attr"):
        for v in item.find("attrdomv"):
            if v.tag == "rdom":
                for u in v.findall("attrunit"):
                    units.append((item.find("attrlabl").text, u.text.lower()))
units = pd.DataFrame(units, columns=["attr", "unit"])

The first five rows of the obtained dataframe is shown below:

	attr	unit
0	CAT_HLR_1	percent
1	CAT_HLR_2	percent
2	CAT_HLR_3	percent
3	CAT_HLR_4	percent
4	CAT_HLR_5	percent