mrmw3 / parfive

An asyncio based parallel file downloader for Python 3.7+

Parfive

A parallel file downloader using asyncio. parfive can handle downloading multiple files in parallel as well as downloading each file in a number of chunks.

Usage

parfive works by creating a downloader object, appending files to it and then running the download. parfive has a synchronous API, but uses asyncio to paralellise downloading the files.

A simple example is:

from parfive import Downloader
dl = Downloader()
dl.enqueue_file("http://data.sunpy.org/sample-data/predicted-sunspot-radio-flux.txt", path="./")
files = dl.download()

Parfive also bundles a CLI. The following example will download the two files concurrently.:

$ parfive 'http://212.183.159.230/5MB.zip' 'http://212.183.159.230/10MB.zip'
$ parfive --help
usage: parfive [-h] [--max-conn MAX_CONN] [--overwrite] [--no-file-progress]
              [--directory DIRECTORY] [--print-filenames]
              URLS [URLS ...]

Parfive, the python asyncio based downloader

positional arguments:
  URLS                  URLs of files to be downloaded.

optional arguments:
  -h, --help            show this help message and exit
  --max-conn MAX_CONN   Number of maximum connections.
  --overwrite           Overwrite if the file exists.
  --no-file-progress    Show progress bar for each file.
  --directory DIRECTORY
                        Directory to which downloaded files are saved.
  --print-filenames     Print successfully downloaded files's names to stdout.

Results

parfive.Downloader.download returns a parfive.Results object, which is a list of the filenames that have been downloaded. It also tracks any files which failed to download.

Handling Errors

If files fail to download, the urls and the response from the server are stored in the Results object returned by parfive.Downloader. These can be used to inform users about the errors. (Note, the progress bar will finish in an incomplete state if a download fails, i.e. it will show 4/5 Files Downloaded).

The Results object is a list with an extra attribute errors, this property returns a list of named tuples, where these named tuples contains the .url and the .response, which is a aiohttp.ClientResponse or a aiohttp.ClientError object.

Installation

parfive is available on PyPI, you can install it with pip:

pip install parfive

or if you want to use FTP downloads:

pip install parfive[ftp]

Requirements

• Python 3.7 or above
• aiohttp
• tqdm
• aioftp (for downloads over FTP)

Licence

MIT Licensed

Authors

parfive was written by Stuart Mumford.