以下是python中下载文件最常用的调用:

urllib。Urlretrieve ('url_to_file'， file_name) urllib2.urlopen(“url_to_file”) requests.get (url) wget。下载(“url”,file_name)

注意:urlopen和urlretrieve在下载大文件(大小为> 500 MB)时表现相对较差。请求。Get将文件存储在内存中，直到下载完成。

在python3中，可以使用urllib3和shutil库。 使用pip或pip3下载它们(取决于python3是否默认)

pip3 install urllib3 shutil

然后运行这段代码

import urllib.request
import shutil

url = "http://www.somewebsite.com/something.pdf"
output_file = "save_this_name.pdf"
with urllib.request.urlopen(url) as response, open(output_file, 'wb') as out_file:
    shutil.copyfileobj(response, out_file)

注意，您下载了urllib3，但在代码中使用了urllib

import os,requests
def download(url):
    get_response = requests.get(url,stream=True)
    file_name  = url.split("/")[-1]
    with open(file_name, 'wb') as f:
        for chunk in get_response.iter_content(chunk_size=1024):
            if chunk: # filter out keep-alive new chunks
                f.write(chunk)


download("https://example.com/example.jpg")

为了这个目的，用纯Python编写了wget库。从2.0版开始，它就为urlretrieve注入了这些特性。

我写了下面的代码，它可以在普通的Python 2或Python 3中工作。

import sys
try:
    import urllib.request
    python3 = True
except ImportError:
    import urllib2
    python3 = False


def progress_callback_simple(downloaded,total):
    sys.stdout.write(
        "\r" +
        (len(str(total))-len(str(downloaded)))*" " + str(downloaded) + "/%d"%total +
        " [%3.2f%%]"%(100.0*float(downloaded)/float(total))
    )
    sys.stdout.flush()

def download(srcurl, dstfilepath, progress_callback=None, block_size=8192):
    def _download_helper(response, out_file, file_size):
        if progress_callback!=None: progress_callback(0,file_size)
        if block_size == None:
            buffer = response.read()
            out_file.write(buffer)

            if progress_callback!=None: progress_callback(file_size,file_size)
        else:
            file_size_dl = 0
            while True:
                buffer = response.read(block_size)
                if not buffer: break

                file_size_dl += len(buffer)
                out_file.write(buffer)

                if progress_callback!=None: progress_callback(file_size_dl,file_size)
    with open(dstfilepath,"wb") as out_file:
        if python3:
            with urllib.request.urlopen(srcurl) as response:
                file_size = int(response.getheader("Content-Length"))
                _download_helper(response,out_file,file_size)
        else:
            response = urllib2.urlopen(srcurl)
            meta = response.info()
            file_size = int(meta.getheaders("Content-Length")[0])
            _download_helper(response,out_file,file_size)

import traceback
try:
    download(
        "https://geometrian.com/data/programming/projects/glLib/glLib%20Reloaded%200.5.9/0.5.9.zip",
        "output.zip",
        progress_callback_simple
    )
except:
    traceback.print_exc()
    input()

注:

支持“进度条”回调。 从我的网站上下载一个4 MB的测试包。zip。

使用urllib.request.urlopen ():

import urllib.request
with urllib.request.urlopen('http://www.example.com/') as f:
    html = f.read().decode('utf-8')

这是使用库的最基本的方法，没有任何错误处理。您还可以执行更复杂的操作，例如更改头文件。

在Python 2中，该方法在urllib2中:

import urllib2
response = urllib2.urlopen('http://www.example.com/')
html = response.read()