Get 'last-modified' from target page's header by Python.

get_last_modified_from_header.py

# -*- coding: utf-8 -*-
"""
改行区切りのURLリストにそれぞれアクセスし，
各ページのheaderにあるlast-modifiedの値を取得する．
"""
import httplib2
import time

# 対象URLのリスト
INPUT_FILE_NAME = "INPUT_FILE_NAME"
# 出力先のファイル
OUTPUT_FILE_NAME = "OUTPUT_FILE_NAME"
# 実行間隔
SLEEP_TIME = 0
# 対象のheader-key
TARGET_KEY = "last-modified"

def main():
    h = httplib2.Http()
    # 対象URLのリストがあるファイルを開く
    with open(INPUT_FILE_NAME, mode="r", encoding="utf-8") as input_file:
        # 検索結果を出力するファイルを開く
        with open(OUTPUT_FILE_NAME, mode="a", encoding="utf-8") as output_file:
            count = 0
            for url in input_file:
                time.sleep(SLEEP_TIME)
                count += 1
                url = url.rstrip()
                # 進行状況確認のため出力
                print(count, url)
                try:
                    # キャッシュを無視
                    response, content = h.request(url, "GET", headers={"cache-control": "no-cache"})
                    # 取得結果を書き込み
                    if TARGET_KEY in response:
                        output_file.write(url + " => " + response[TARGET_KEY] + ",\n")
                    else:
                        output_file.write(url + " => no response[" + TARGET_KEY + "]\n")
                except httplib2.ServerNotFoundError:
                    output_file.write(url + " => ServerNotFoundError\n")
                    continue
                except httplib2.ssl.CertificateError:
                    output_file.write(url + " => httplib2.ssl.CertificateError\n")
                    continue
                except OSError:
                    output_file.write(url + " OSError\n")
                    continue
                continue


if __name__ == "__main__":
    main()