我需要在 Python 3 的文件下载期间显示进度。 我在 Stackoverflow 上看过一些主题,但考虑到我是编程新手,没有人发布完整的示例,只是其中的一部分,或者我可以在 Python 3 上工作的示例,没有一个对我有好处。 .
附加信息:
好的,所以我有这个:
from urllib.request import urlopen
import configparser
#checks for files which need to be downloaded
print(' Downloading...')
file = urlopen(file_url)
#progress bar here
output = open('downloaded_file.py','wb')
output.write(file.read())
output.close()
os.system('downloaded_file.py')
脚本通过python命令行运行
最佳答案
有urlretrieve()
将 url 下载到文件并允许指定 reporthook 回调以报告进程:
#!/usr/bin/env python3
import sys
from urllib.request import urlretrieve
def reporthook(blocknum, blocksize, totalsize):
readsofar = blocknum * blocksize
if totalsize > 0:
percent = readsofar * 1e2 / totalsize
s = "\r%5.1f%% %*d / %d" % (
percent, len(str(totalsize)), readsofar, totalsize)
sys.stderr.write(s)
if readsofar >= totalsize: # near the end
sys.stderr.write("\n")
else: # total size is unknown
sys.stderr.write("read %d\n" % (readsofar,))
urlretrieve(url, 'downloaded_file.py', reporthook)
这是一个 GUI 进度条:
import sys
from threading import Event, Thread
from tkinter import Tk, ttk
from urllib.request import urlretrieve
def download(url, filename):
root = progressbar = quit_id = None
ready = Event()
def reporthook(blocknum, blocksize, totalsize):
nonlocal quit_id
if blocknum == 0: # started downloading
def guiloop():
nonlocal root, progressbar
root = Tk()
root.withdraw() # hide
progressbar = ttk.Progressbar(root, length=400)
progressbar.grid()
# show progress bar if the download takes more than .5 seconds
root.after(500, root.deiconify)
ready.set() # gui is ready
root.mainloop()
Thread(target=guiloop).start()
ready.wait(1) # wait until gui is ready
percent = blocknum * blocksize * 1e2 / totalsize # assume totalsize > 0
if quit_id is None:
root.title('%%%.0f %s' % (percent, filename,))
progressbar['value'] = percent # report progress
if percent >= 100: # finishing download
quit_id = root.after(0, root.destroy) # close GUI
return urlretrieve(url, filename, reporthook)
download(url, 'downloaded_file.py')
在 Python 3.3 上 urlretrieve()
有不同的 reporthook
接口(interface) ( see issue 16409 )。要解决此问题,您可以通过 FancyURLopener
访问以前的界面:
from urllib.request import FancyURLopener
urlretrieve = FancyURLopener().retrieve
要在同一个线程中更新进度条,您可以内联 urlretrieve()
代码:
from tkinter import Tk, ttk
from urllib.request import urlopen
def download2(url, filename):
response = urlopen(url)
totalsize = int(response.headers['Content-Length']) # assume correct header
outputfile = open(filename, 'wb')
def download_chunk(readsofar=0, chunksize=1 << 13):
# report progress
percent = readsofar * 1e2 / totalsize # assume totalsize > 0
root.title('%%%.0f %s' % (percent, filename,))
progressbar['value'] = percent
# download chunk
data = response.read(chunksize)
if not data: # finished downloading
outputfile.close()
root.destroy() # close GUI
else:
outputfile.write(data) # save to filename
# schedule to download the next chunk
root.after(0, download_chunk, readsofar + len(data), chunksize)
# setup GUI to show progress
root = Tk()
root.withdraw() # hide
progressbar = ttk.Progressbar(root, length=400)
progressbar.grid()
# show progress bar if the download takes more than .5 seconds
root.after(500, root.deiconify)
root.after(0, download_chunk)
root.mainloop()
download2(url, 'downloaded_file.py')
关于python - 下载 Python 3 的进度条,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/13881092/