Question

我可以找到一些doc解释如何使用tqdm包，但是我无法从中了解如何在线下载数据时生成进度表。

以下是我从ResidentMario复制的用于下载数据的示例代码

def download_file(url, filename):
    """
    Helper method handling downloading large files from `url` to `filename`. Returns a pointer to `filename`.
    """
    r = requests.get(url, stream=True)
    with open(filename, 'wb') as f:
        for chunk in r.iter_content(chunk_size=1024): 
            if chunk: # filter out keep-alive new chunks
                f.write(chunk)
    return filename


dat = download_file("https://data.cityofnewyork.us/api/views/h9gi-nx95/rows.csv?accessType=DOWNLOAD",
                    "NYPD Motor Vehicle Collisions.csv")

有谁能告诉我如何在这里使用tqdm包来显示下载进度？

由于

Answer 1

截至目前，我做了类似的事情：

def download_file(url, filename):
    """
    Helper method handling downloading large files from `url` to `filename`. Returns a pointer to `filename`.
    """
    chunkSize = 1024
    r = requests.get(url, stream=True)
    with open(filename, 'wb') as f:
        pbar = tqdm( unit="B", total=int( r.headers['Content-Length'] ) )
        for chunk in r.iter_content(chunk_size=chunkSize): 
            if chunk: # filter out keep-alive new chunks
                pbar.update (len(chunk))
                f.write(chunk)
    return filename

Answer 2

感谢silmaril，但下面的工作对我来说更有意义。

def download_file(url, filename):
    testread = requests.head(url_r)     # A HEAD request only downloads the headers
    filelength = int(testread.headers['Content-length'])

    r = requests.get(url, stream=True)  # actual download full file

    with open(filename, 'wb') as f:
        pbar = tqdm(total=int(filelength/1024))
        for chunk in r.iter_content(chunk_size=1024):
            if chunk:                   # filter out keep-alive new chunks
                pbar.update ()
                f.write(chunk)

如何在python中使用`tqdm`来显示在线下载数据时的进度？

2 个答案: