data-downloader 0.1.2

Make downloading scientific data much easier

data-downloader

Make downloading scientific data much easier

1. Installation

It is recommended to use the latest version of pip to install data_downloader.

pip install data_downloader

2. Usage

All downloading functions are in data_downloader.downloader . So import downloader at the beginning.

from data_downloader import downloader

2.1 Netrc

If the website needs to log in, you can add a record to a .netrc file in your home which contains your login information to avoid supplying username and password each time you download data.

To view existing hosts in .netrc file:

netrc = downloader.Netrc()
print(netrc.hosts)

To add a record

netrc.add(self, host, login, password, account=None, overwrite=False)

If you want to update a record, set tha parameter overwrite=True

for NASA data user:

netrc.add('urs.earthdata.nasa.gov','your_username','your_password')

You can use the downloader.get_url_host(url) to get the host name when you don't know the host of the website:

host = downloader.get_url_host(url)

To remove a record

netrc.remove(self, host)

To clear all records

netrc.clear()

Example:

In [2]: netrc = downloader.Netrc()
In [3]: netrc.hosts
Out[3]: {}

In [4]: netrc.add('urs.earthdata.nasa.gov','username','passwd') 

In [5]: netrc.hosts
Out[5]: {'urs.earthdata.nasa.gov': ('username', None, 'passwd')}

In [6]: netrc
Out[6]:
machine urs.earthdata.nasa.gov
	login username
	password passwd

# This command only for linux user
In [7]: !cat ~/.netrc
machine urs.earthdata.nasa.gov
	login username
	password passwd

In [8]: url = 'https://gpm1.gesdisc.eosdis.nasa.gov/daac-bin/OTF/HTTP_services.cgi?FILENAME=%2Fdata%2FGPM_L3%2FGPM_3IMERGM.06%2F2000%2F3B-MO.MS.MRG.3IMERG.20000601-S000000-E235959.06.V06B.HDF5&FORMAT=bmM0Lw&BBOX=31.904%2C99.492%2C35.771%2C105.908&LABEL=3B-MO.MS.MRG.3IMERG.20000601-S000000-E235959.06.V06B.HDF5.SUB.nc4&SHORTNAME=GPM_3IMERGM&SERVICE=L34RS_GPM&VERSION=1.02&DATASET_VERSION=06&VARIABLES=precipitation'

In [9]: downloader.get_url_host(url)
Out[9]: 'gpm1.gesdisc.eosdis.nasa.gov'

In [10]: netrc.add(downloader.get_url_host(url),'username','passwd')

In [11]: netrc
Out[11]:
machine urs.earthdata.nasa.gov
        login username
        password passwd
machine gpm1.gesdisc.eosdis.nasa.gov
        login username
        password passwd

In [12]: netrc.add(downloader.get_url_host(url),'username','new_passwd')
>>> Warning: test_host existed, nothing will be done. If you want to overwrite the existed record, set overwrite=True

In [13]: netrc
Out[13]:
machine urs.earthdata.nasa.gov
        login username
        password passwd
machine gpm1.gesdisc.eosdis.nasa.gov
        login username
        password passwd

In [14]: netrc.add(downloader.get_url_host(url),'username','new_passwd',overwrite=True)

In [15]: netrc
Out[15]:
machine urs.earthdata.nasa.gov
        login username
        password passwd
machine gpm1.gesdisc.eosdis.nasa.gov
        login username
        password new_passwd

In [16]: netrc.remove(downloader.get_url_host(url))

In [17]: netrc
Out[17]:
machine urs.earthdata.nasa.gov
        login username
        password passwd

In [18]: netrc.clear()

In [19]: netrc.hosts
Out[19]: {}

2.2 download_data

This function is design for downloading a single file. Try to use download_datas, mp_download_datas or async_download_datas function if you have a lot of files to download

downloader.download_data(url, folder=None, file_name=None, client=None)

Parameters:

url: str
    url of web file
folder: str
    the folder to store output files. Default current folder. 
file_name: str
    the file name. If None, will parse from web response or url.
    file_name can be the absolute path if folder is None.
client: httpx.Client() object
    client maintaining connection. Default None

Example:

In [6]: url = 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_131313/interferograms/20141117_20141211/20141117_201
   ...: 41211.geo.unw.tif'
   ...:  
   ...: folder = 'D:\\data'
   ...: downloader.download_data(url,folder)

20141117_20141211.geo.unw.tif:   2%|▌                   | 455k/22.1M [00:52<42:59, 8.38kB/s]

2.3 download_datas

download datas from a list like object that contains urls. This function will download files one by one.

downloader.download_datas(urls, folder=None, file_names=None):

Patameters:

urls:  iterator
    iterator contains urls
folder: str
    the folder to store output files. Default current folder.
file_names: iterator
    iterator contains names of files. Leaving it None if you want the program to parse 
    them fromwebsite. file_names can cantain the absolute paths if folder is None.

Examples:

In [12]: from data_downloader import downloader 
    ...:  
    ...: urls=['http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_131313/interferograms/20141117_20141211/20141117_20
    ...: 141211.geo.unw.tif', 
    ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_131313/interferograms/20141024_20150221/20141024_20150221
    ...: .geo.unw.tif', 
    ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_131313/interferograms/20141024_20150128/20141024_20150128
    ...: .geo.cc.tif', 
    ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_131313/interferograms/20141024_20150128/20141024_20150128
    ...: .geo.unw.tif', 
    ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_131313/interferograms/20141211_20150128/20141211_20150128
    ...: .geo.cc.tif', 
    ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_131313/interferograms/20141117_20150317/20141117_20150317
    ...: .geo.cc.tif', 
    ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_131313/interferograms/20141117_20150221/20141117_20150221
    ...: .geo.cc.tif']  
    ...:  
    ...: folder = 'D:\\data' 
    ...: downloader.download_datas(urls,folder)

20141117_20141211.geo.unw.tif:   6%|█           | 1.37M/22.1M [03:09<2:16:31, 2.53kB/s]

2.4 mp_download_datas

Download files simultaneously using multiprocessing.

downloader.mp_download_datas(urls, folder=None, file_names=None, ncore=None, desc='')

Parameters:

urls:  iterator
    iterator contains urls
folder: str
    the folder to store output files. Default current folder.
file_names: iterator
    iterator contains names of files. Leaving it None if you want the program to parse
    them from website. file_names can cantain the absolute paths if folder is None.
ncore: int
    Number of cores for parallel downloading. If ncore is None, then the number returned
    by os.cpu_count() is used. Defalut None.

Example:

In [12]: from data_downloader import downloader 
    ...:  
    ...: urls=['http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_131313/interferograms/20141117_20141211/20141117_20
    ...: 141211.geo.unw.tif', 
    ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_131313/interferograms/20141024_20150221/20141024_20150221
    ...: .geo.unw.tif', 
    ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_131313/interferograms/20141024_20150128/20141024_20150128
    ...: .geo.cc.tif', 
    ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_131313/interferograms/20141024_20150128/20141024_20150128
    ...: .geo.unw.tif', 
    ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_131313/interferograms/20141211_20150128/20141211_20150128
    ...: .geo.cc.tif', 
    ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_131313/interferograms/20141117_20150317/20141117_20150317
    ...: .geo.cc.tif', 
    ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_131313/interferograms/20141117_20150221/20141117_20150221
    ...: .geo.cc.tif']  
    ...:  
    ...: folder = 'D:\\data' 
    ...: downloader.mp_download_datas(urls,folder)

 >>> 12 parallel downloading
 >>> Total | :   0%|                                         | 0/7 [00:00<?, ?it/s]
20141211_20150128.geo.cc.tif:  15%|██▊                | 803k/5.44M [00:00<?, ?B/s]

2.5 async_download_datas

Download files simultaneously with asynchronous mode. The website that don't support resuming breakpoint and need to log in may have the problem while downloading. You can use download_datas or mp_download_datasinstead

downloader.async_download_datas(urls, folder=None, file_names=None, limit=30, desc='')

Parameters:

urls:  iterator
    iterator contains urls
folder: str 
    the folder to store output files. Default current folder.
file_names: iterator
    iterator contains names of files. Leaving it None if you want the program 
    to parse them from website. file_names can cantain the absolute paths if folder is None.
limit: int
    the number of files downloading simultaneously
desc: str
    description of datas downloading

Example:

In [3]: from data_downloader import downloader 
   ...:  
   ...: urls=['http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049
   ...: _131313/interferograms/20141117_20141211/20141117_20141211.geo.unw.tif', 
   ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_13131
   ...: 3/interferograms/20141024_20150221/20141024_20150221.geo.unw.tif', 
   ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_13131
   ...: 3/interferograms/20141024_20150128/20141024_20150128.geo.cc.tif', 
   ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_13131
   ...: 3/interferograms/20141024_20150128/20141024_20150128.geo.unw.tif', 
   ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_13131
   ...: 3/interferograms/20141211_20150128/20141211_20150128.geo.cc.tif', 
   ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_13131
   ...: 3/interferograms/20141117_20150317/20141117_20150317.geo.cc.tif', 
   ...: 'http://gws-access.ceda.ac.uk/public/nceo_geohazards/LiCSAR_products/106/106D_05049_13131
   ...: 3/interferograms/20141117_20150221/20141117_20150221.geo.cc.tif']  
   ...:  
   ...: folder = 'D:\\data' 
   ...: downloader.async_download_datas(urls,folder,limit=3,desc='interferograms')

>>> Total | Interferograms :   0%|                          | 0/7 [00:00<?, ?it/s]
    20141024_20150221.geo.unw.tif:  11%|▌    | 2.41M/21.2M [00:11<41:44, 7.52kB/s]
    20141117_20141211.geo.unw.tif:   9%|▍    | 2.06M/22.1M [00:11<25:05, 13.3kB/s]
    20141024_20150128.geo.cc.tif:  36%|██▏   | 1.98M/5.42M [00:12<04:17, 13.4kB/s] 
    20141117_20150317.geo.cc.tif:   0%|               | 0.00/5.44M [00:00<?, ?B/s]
    20141117_20150221.geo.cc.tif:   0%|               | 0.00/5.47M [00:00<?, ?B/s]
    20141024_20150128.geo.unw.tif:   0%|              | 0.00/23.4M [00:00<?, ?B/s]
    20141211_20150128.geo.cc.tif:   0%|               | 0.00/5.44M [00:00<?, ?B/s]

2.6 status_ok

Simultaneously detecting whether the given links are accessable.

status_ok(urls, limit=200, timeout=60)

Parameters

urls: iterator
    iterator contains urls
limit: int
    the number of urls connecting simultaneously
timeout: int
    Request to stop waiting for a response after a given number of seconds

Return:

a list of results (True or False)

Example:

In [1]: from data_downloader import downloader
   ...: import numpy as np
   ...: 
   ...: urls = np.array(['https://www.baidu.com',
   ...: 'https://www.bai.com/wrongurl',
   ...: 'https://cn.bing.com/',
   ...: 'https://bing.com/wrongurl',
   ...: 'https://bing.com/'] )
   ...: 
   ...: status_ok = downloader.status_ok(urls)
   ...: urls_accessable = urls[status_ok]
   ...: print(urls_accessable)

['https://www.baidu.com' 'https://cn.bing.com/' 'https://bing.com/']