python 下载文件的多种方法汇总

import requests

# 图片来自bing.com
url = 'https://cn.bing.com/th?id=OHR.DerwentIsle_EN-CN8738104578_400x240.jpg'

def requests_download():

  content = requests.get(url).content

  with open('pic_requests.jpg', 'wb') as file:
    file.write(content)

from urllib import request

# 图片来自bing.com
url = 'https://cn.bing.com/th?id=OHR.DerwentIsle_EN-CN8738104578_400x240.jpg'

def urllib_download():
  request.urlretrieve(url, 'pic_urllib.jpg')

def urllib3_download():
  # 创建一个连接池
  poolManager = urllib3.PoolManager()

  resp = poolManager.request('GET', url)

  with open("pic_urllib3.jpg", "wb") as file:
    file.write(resp.data)

  resp.release_conn()

import wget

# 图片来自bing.com
url = 'https://cn.bing.com/th?id=OHR.DerwentIsle_EN-CN8738104578_400x240.jpg'

def wget_download():
  wget.download(url, out='pic_wget.jpg')

python -m wget https://cn.bing.com/th?id=OHR.DerwentIsle_EN-CN8738104578_400x240.jpg

import requests

def steam_download():
  # vscode 客户端
  url = 'https://vscode.cdn.azure.cn/stable/e5a624b788d92b8d34d1392e4c4d9789406efe8f/VSCodeUserSetup-x64-1.51.1.exe'

  with requests.get(url, stream=True) as r:
    with open('vscode.exe', 'wb') as flie:
      # chunk_size 指定写入大小每次写入 1024 * 1024 bytes
      for chunk in r.iter_content(chunk_size=1024*1024):
        if chunk:
          flie.write(chunk)

from tqdm import tqdm

def tqdm_download():

  url = 'https://vscode.cdn.azure.cn/stable/e5a624b788d92b8d34d1392e4c4d9789406efe8f/VSCodeUserSetup-x64-1.51.1.exe'

  resp = requests.get(url, stream=True)

  # 获取文件大小
  file_size = int(resp.headers['content-length'])
  
  with tqdm(total=file_size, unit='B', unit_scale=True, unit_divisor=1024, ascii=True, desc='vscode.exe') as bar:
    with requests.get(url, stream=True) as r:
      with open('vscode.exe', 'wb') as fp:
        for chunk in r.iter_content(chunk_size=512):
          if chunk:
            fp.write(chunk)
            bar.update(len(chunk))

Range:[unit=first byte pos] - [last byte pos]，即 Range = 开始字节位置-结束字节位置，单位：bytes

from tqdm import tqdm

def duan_download():
  url = 'https://vscode.cdn.azure.cn/stable/e5a624b788d92b8d34d1392e4c4d9789406efe8f/VSCodeUserSetup-x64-1.51.1.exe'

  r = requests.get(url, stream=True)

  # 获取文件大小
  file_size = int(r.headers['content-length'])

  file_name = 'vscode.exe'
  # 如果文件存在获取文件大小，否在从 0 开始下载，
  first_byte = 0
  if os.path.exists(file_name):
    first_byte = os.path.getsize(file_name)
    
  # 判断是否已经下载完成
  if first_byte >= file_size:
    return

  # Range 加入请求头
  header = {"Range": f"bytes={first_byte}-{file_size}"}

  # 加了一个 initial 参数
  with tqdm(total=file_size, unit='B', initial=first_byte, unit_scale=True, unit_divisor=1024, ascii=True, desc=file_name) as bar:
    # 加 headers 参数
    with requests.get(url, headers = header, stream=True) as r:
      with open(file_name, 'ab') as fp:
        for chunk in r.iter_content(chunk_size=512):
          if chunk:
            fp.write(chunk)
            bar.update(len(chunk))