Python之下载文件

本文主要是介绍Python之下载文件，对大家解决编程问题具有一定的参考价值，需要的程序猿们随着小编来一起学习吧！

自动化测试过程中发现避免不了需要手动操作的部分，如手动下载最新的APK文件进行smoke测试，而往往新的版本是在夜间进行的，等到早上上班后再进行下载进行smoke测试的话时间就浪费了，因此需要有个脚本自动检测是否有新版本，并自动下载进行smoke测试。可使用requests方法实现下载：

# -*- coding:utf-8 -*-
import requests
import os
from requests.auth import HTTPBasicAuth
import time
from sys import argv
from time import sleep


url = "http://xxxxx.com" \
      "version.txt"
base_download_url = "http://xxxxx.com/new.apk"
user_Agent = "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 " \
             "Safari/537.36 "
header1 = {
    "Referer": url,
    "User-Agent": user_Agent

}
header2 = {
    "Referer": base_download_url,
    "User-Agent": user_Agent

}

serial_no = argv[1]
user = argv[2]
password = argv[3]

# 获取当前版本号
version = os.popen("adb -s " + serial_no + " shell pm dump com.mediatek.wwtv.tvcenter | findstr versionName")
current_version_full = version.read().rsplit("\n")[0].rsplit("=")[1]
current_version = current_version_full.rsplit(".")[2]

print ("Current version: " + current_version_full)
local = os.getcwd()
status = True
# requests.adapters.DEFAULT_RETRIES = 5
# s = requests.session()
# s.keep_alive = False
while status:

    response_version = requests.get(url, headers=header1, auth=HTTPBasicAuth(user, password))
    response_apk = requests.get(base_download_url, headers=header2, auth=HTTPBasicAuth(user, password))

    filename = os.path.basename(url)
    apk = os.path.basename(base_download_url)
    # 下载 Litv_apk_LiveTV.txt，以便检查最新版本
    with open(filename, "wb") as txt:
        txt.write(response_version.content)
    version_file = open(local + "/version.txt", "r")
    lines = version_file.readlines()

    for line in lines:
        # 检查是否有新版本
        if line.find("current_version") != -1:
            new_version_full = line.rsplit(" = ")[1].replace('"', '').replace('\n', '')
            new_version = line.replace('"', '').rsplit(".")[2]

            new_version = int(new_version)
            print ("Checking New Version......")
            if new_version > int(current_version):

                apk_size = int(response_apk.headers["content-length"])

                print ("New version found: %s,start downloading......" % new_version_full)
                with open(apk, "wb") as apk:
                    apk.write(response_apk.content)
                    down_size = os.path.getsize(local + "/xxx.apk")

                    progress = str(down_size * 100 / apk_size)
                    print (progress + "% completed")
   				print ("100% completed,start install xxx.apk")
                os.system("adb -s " + serial_no + " install xxx.apk")
                status = False

            else:
                print ("The version of xxx is up to date, check later please.......\n")
                sleep(60*60)
print ("====================xxx smoke test start=====================")

此代码是从jenkins中检测新版本并下载，其中apk的版本信息放置在version.txt中：current_version = “x.x.x”
apk 下载过程中未限制字节流，不能直观体现下载进度

且下载较大的文件会出现下载不完整的情况，此时需要进行字节流限制（每次下载的大小）

chunk_size = 1024000# 每次下载1M
with open(apk, "wb") as apk:
    for chunk in response_apk.iter_content(chunk_size=chunk_size):
        if chunk:
            apk.write(chunk)
            down_size = os.path.getsize(local + "/xxx.apk")
            progress = str(down_size*100/apk_size)
            print (progress + "% completed")

结果如下：

这篇关于Python之下载文件的文章就介绍到这儿，希望我们推荐的文章对大家有所帮助，也希望大家多多支持为之网！