关于Python下载大文件时哪种方式速度更快

def download_file(url):
    local_filename = url.split('/')[-1]
    # 注意传入参数 stream=True
    with requests.get(url, stream=True) as r:
        r.raise_for_status()
        with open(local_filename, 'wb') as f:
            for chunk in r.iter_content(chunk_size=8192): 
                f.write(chunk)
    return local_filename

def download_file(url):
    local_filename = url.split('/')[-1]
    # 注意传入参数 stream=True
    with requests.get(url, stream=True) as r:
        r.raise_for_status()
        with open(local_filename, 'w') as f:
            for chunk in r.iter_content(): 
                if chunk:
                    f.write(chunk.decode("utf-8"))
    return local_filename

import requests
import shutil

def download_file(url):
    local_filename = url.split('/')[-1]
    with requests.get(url, stream=True) as r:
        with open(local_filename, 'wb') as f:
            shutil.copyfileobj(r.raw, f)

    return local_filename

response.raw.read = functools.partial(response.raw.read, decode_content=True)