Stale tumblr checker

#!/usr/bin/env python3
# encoding: utf-8

from urllib.request import urlopen
from urllib.parse import urlparse, urlencode
from http.client import HTTPException
from datetime import datetime
from sys import stdout, argv
from os import getenv

import logging
import json

API_KEY = getenv("TUMBLR_KEY", "8YUsKJvcJxo2MDwmWMDiXZGuMuIbeCwuQGP5ZHSEA4jBJPMnJT")
PARAMS = urlencode({ "api_key": API_KEY })

RFC3339_STRING = "%Y-%m-%dT%H:%M:%S.%fZ"

def get_logger(name, level=logging.INFO):
    log_format = logging.Formatter('[%(asctime)s] (%(name)s) %(levelname)s: %(message)s')

    std_output = logging.StreamHandler(stdout)
    std_output.setFormatter(log_format)
    std_output.setLevel(level)

    logger = logging.getLogger(name)
    logger.setLevel(logging.DEBUG)
    logger.addHandler(std_output)
    return logger

# Source file parsing
def parse_list(filename):
    result = []

    with open(filename, 'r', encoding="UTF-8") as reader:
        for line in reader:
            clean_line = line.strip()
            if clean_line:
                result.append(urlparse(clean_line).netloc or clean_line)

    return frozenset(result)

def parse_blog(blog_url):
    log = get_logger(blog_url)

    request = "https://api.tumblr.com/v2/blog/{uri}/info?{params}".format(
        params = PARAMS,
        uri = blog_url
    )

    try:
        response = urlopen(request)
    except (HTTPException, OSError) as err:
        log.error("Error fetching blog info: {err}".format(err=err))
        return None

    content_type = response.info().get_content_type()

    if content_type != "application/json":
        log.error("Unexpected Content-Type: {type}".format(type=content_type))
        return None

    try:
        data = json.load(response)
    except JSONDecodeError as err:
        log.error("Error parsing blog info: {err}".format(err=err))
        return None

    status = data.get("meta", {}).get("status", response.getcode())

    if status != 200:
        log.error("Error processing {url}: {data}".format(url=url, data=data))
        return None

    info = data.get("response", {}).get("blog", {})
    post_count = info.get("posts", 0)

    if post_count < 1:
        return None

    return ','.join([
        blog_url,
        str(post_count),
        datetime.utcfromtimestamp(int(info.get("updated", 0))).strftime(RFC3339_STRING)
    ])


if __name__ == "__main__":
    # Parsing arguments
    try:
       source_file = argv[1]
    except IndexError:
       source_file = "tumblrs_raw.txt"

    try:
        dest_file = argv[2]
    except IndexError:
        dest_file = "tumblrs_alive.txt"

    # Checking blogs
    with open(dest_file, 'a', encoding="UTF-8") as out_file:
        print("url,post_count,last_updated", file=out_file)
        for url in sorted(parse_list(source_file)):
            if url:
                csv_line = parse_blog(url)
                if csv_line:
                    print(blog_url, file=out_file)