Selenium (Python) - waiting for a download process to complete using Chrome web driver

Question

I\'m using selenium and python via chromewebdriver (windows) in order to automate a task of downloading large amount of files from different pages. My code works, but the so

Answer 1

import os
from selenium import webdriver
from selenium.webdriver.support.wait import WebDriverWait

class MySeleniumTests(unittest.TestCase):

    selenium = None

    @classmethod
    def setUpClass(cls):
        cls.selenium = webdriver.Firefox(...)

    ...

    def test_download(self):
        os.chdir(self.download_path) # default download directory

        # click the button
        self.selenium.get(...)
        self.selenium.find_element_by_xpath(...).click()

        # waiting server for finishing inner task
        def download_begin(driver):
            if len(os.listdir()) == 0:
                time.sleep(0.5)
                return False
            else:
                return True
        WebDriverWait(self.selenium, 120).until(download_begin) # the max wating time is 120s

        # waiting server for finishing sending.
        # if size of directory is changing,wait
        def download_complete(driver):
            sum_before=-1
            sum_after=sum([os.stat(file).st_size for file in os.listdir()])
            while sum_before != sum_after:
                time.sleep(0.2)
                sum_before = sum_after
                sum_after = sum([os.stat(file).st_size for file in os.listdir()])
            return True
        WebDriverWait(self.selenium, 120).until(download_complete)  # the max wating time is 120s

You must do these thing

1. Wait for server to finish inner business( for example, query from database).
2. Wait for server to finish sending the files.

(my English is not very well)