Selenium (Python) - waiting for a download process to complete using Chrome web driver
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 solution is far from ideal: the function below clicks on the website button that initiating a java script function that generating a PDF file and then downloading it.
I had to use a static wait in order to wait for the download to be completed (ugly) I cannot check the file system in order to verify when the download is completed since i'm using multi threading (downloading lot's of files from different pages at once) and also the the name of the files is generated dynamically in the website itself.
My code:
def file_download(num, drivervar):
Counter += 1
try:
drivervar.get(url[num])
download_button = WebDriverWait(drivervar, 20).until(EC.element_to_be_clickable((By.ID, 'download button ID')))
download_button.click()
time.sleep(10)
except TimeoutException: # Retry once
print('Timeout in thread number: ' + str(num) + ', retrying...')
.....
Is it possible to determine download completion in webdriver? I want to avoid using time.sleep(x).
Thanks a lot.
You can get the status of each download by visiting chrome://downloads/ with the driver.
To wait for all the downloads to finish and to list all the paths:
def every_downloads_chrome(driver):
if not driver.current_url.startswith("chrome://downloads"):
driver.get("chrome://downloads/")
return driver.execute_script("""
var items = document.querySelector('downloads-manager')
.shadowRoot.getElementById('downloadsList').items;
if (items.every(e => e.state === "COMPLETE"))
return items.map(e => e.fileUrl || e.file_url);
""")
# waits for all the files to be completed and returns the paths
paths = WebDriverWait(driver, 120, 1).until(every_downloads_chrome)
print(paths)
Was updated to support changes till version 81.
I have had the same problem and found a solution. You can check weither or not a .crdownload is in your download folder. If there are 0 instances of a file with .crdownload extension in the download folder then all your downloads are completed. This only works for chrome and chromium i think.
def downloads_done():
while True:
for filename in os.listdir("/downloads"):
if ".crdownload" in i:
time.sleep(0.5)
downloads_done()
Whenever you call downloads_done() it will loop itself untill all downloads are completed. If you are downloading massive files like 80 gigabytes then i don't recommend this because then the function can reach maximum recursion depth.
2020 edit:
def wait_for_downloads():
print("Waiting for downloads", end="")
while any([filename.endswith(".crdownload") for filename in
os.listdir("/downloads")]):
time.sleep(2)
print(".", end="")
print("done!")
The "end" keyword argument in print() usually holds a newline but we replace it. While there are no filenames in the /downloads folder that end with .crdownload sleep for 2 seconds and print one dot without newline to console
I don't really recommend using selenium anymore after finding out about requests but if it's a very heavily guarded site with cloudflare and captchas etc then you might have to resort to selenium.
With Chrome 80, I had to change the answer from @florent-b by the code below:
def every_downloads_chrome(driver):
if not driver.current_url.startswith("chrome://downloads"):
driver.get("chrome://downloads/")
return driver.execute_script("""
return document.querySelector('downloads-manager')
.shadowRoot.querySelector('#downloadsList')
.items.filter(e => e.state === 'COMPLETE')
.map(e => e.filePath || e.file_path || e.fileUrl || e.file_url);
""")
I believe this is retro-compatible, I mean this shall be working with older versions of Chrome.
There are issues with opening chrome://downloads/ when running Chrome in headless mode.
The following function uses a composite approach that works whether the mode is headless or not, choosing the better approach available in each mode.
It assumes that the caller clears all files downloaded at file_download_path after each call to this function.
import os
import logging
from selenium.webdriver.support.ui import WebDriverWait
def wait_for_downloads(driver, file_download_path, headless=False, num_files=1):
max_delay = 60
interval_delay = 0.5
if headless:
total_delay = 0
done = False
while not done and total_delay < max_delay:
files = os.listdir(file_download_path)
# Remove system files if present: Mac adds the .DS_Store file
if '.DS_Store' in files:
files.remove('.DS_Store')
if len(files) == num_files and not [f for f in files if f.endswith('.crdownload')]:
done = True
else:
total_delay += interval_delay
time.sleep(interval_delay)
if not done:
logging.error("File(s) couldn't be downloaded")
else:
def all_downloads_completed(driver, num_files):
return driver.execute_script("""
var items = document.querySelector('downloads-manager').shadowRoot.querySelector('#downloadsList').items;
var i;
var done = false;
var count = 0;
for (i = 0; i < items.length; i++) {
if (items[i].state === 'COMPLETE') {count++;}
}
if (count === %d) {done = true;}
return done;
""" % (num_files))
driver.execute_script("window.open();")
driver.switch_to_window(driver.window_handles[1])
driver.get('chrome://downloads/')
# Wait for downloads to complete
WebDriverWait(driver, max_delay, interval_delay).until(lambda d: all_downloads_completed(d, num_files))
# Clear all downloads from chrome://downloads/
driver.execute_script("""
document.querySelector('downloads-manager').shadowRoot
.querySelector('#toolbar').shadowRoot
.querySelector('#moreActionsMenu')
.querySelector('button.clear-all').click()
""")
driver.close()
driver.switch_to_window(driver.window_handles[0])