多个单行循环

Question

I am using this data: NVD CVE data

My code is:

import json
with open('nvdcve-1.0-2018.json') as f:
    CVE = json.loads(f.read())

for x in CVE["CVE_Items"]:
    if x["cve"]["affects"]["vendor"]["vendor_data"]: # Check data exists
        description = x["cve"]["description"]["description_data"][0]["value"]
        cve = x["cve"]["CVE_data_meta"]["ID"]
        vendor = x["cve"]["affects"]["vendor"]["vendor_data"][0]["vendor_name"]
        product = x["cve"]["affects"]["vendor"]["vendor_data"][0]["product"]["product_data"][0]["product_name"]
        version = x["cve"]["affects"]["vendor"]["vendor_data"][0]["product"]["product_data"][0]["version"]["version_data"]
        version = [x["version_value"] for x in version]
        references = [x["url"] for x in x["cve"]["references"]["reference_data"]]
        print references

Expected output

[u'https://github.com/D0neMkj/POC_BSOD/tree/master/Advanced%20SystemCare%20Utimate/Monitor_win7_x64.sys-0x9c4060d0']

[u'https://github.com/D0neMkj/POC_BSOD/tree/master/Advanced%20SystemCare%20Utimate/Monitor_win7_x64.sys-0x9c402004']

[u'https://github.com/D0neMkj/POC_BSOD/tree/master/Advanced%20SystemCare%20Utimate/Monitor_win7_x86.sys-0x9c4060c4']

...
...

The code returns this error

Traceback (most recent call last):
  File "<stdin>", line 9, in <module>
KeyError: 'cve'

The key 'cve' does exist:

>>> for x in CVE["CVE_Items"]:
...     x["cve"].keys()
...
[u'description', u'data_type', u'affects', u'data_format', u'problemtype', u'data_version', u'references', u'CVE_data_meta']
[u'description', u'data_type', u'affects', u'data_format', u'problemtype', u'data_version', u'references', u'CVE_data_meta']
[u'description', u'data_type', u'affects', u'data_format', u'problemtype', u'data_version', u'references', u'CVE_data_meta']
...
...

If I remove the two version = lines (11-12), the code works as expected.

I'm thinking the issue is more likely to be me, rather than Python, but I'd like to understand why this error is raised when using multiple single-line for loops?

Answer 1

version = [x["version_value"] for x in version]
references = [x["url"] for x in x["cve"]["references"]["reference_data"]]

You're using x too often. Use a different name for the loop variables.

version = [v["version_value"] for v in version]
references = [r["url"] for r in x["cve"]["references"]["reference_data"]]