pds4_tools.utils.data_access module

Functions

download_file(url[, force, block_size, timeout])

Download a remote file from a URL.

is_supported_url(string)

Check if a string is a supported URL.

clear_download_cache([urls])

Clears the data file cache by deleting the local file(s).

Details

download_file(url, force=False, block_size=65536, timeout=10)[source]

Download a remote file from a URL.

Files are downloaded into a local cache location, and deleted upon Python interpreter exit. Uses is_supported_url to determine supported URL schemes.

Parameters:
urlstr or unicode

A supported remote URL to download.

forcebool, optional

Re-download file even if the URL is already cached. Defaults to None.

block_sizeint, optional

The block-size of each remote read command, in bytes. Defaults to 64 KB.

timeoutint, optional

A timeout in seconds for blocking operations like the connection attempt. Defaults to 10 seconds.

Returns:
str or unicode

Path to the local (cache) location of the downloaded file.

Notes

The cache location can be customized via the PDS4TOOLSCACHEDIR environment variable. Partially adapted from astropy.utils.data.download_file.

is_supported_url(string)[source]

Check if a string is a supported URL.

Parameters:
stringstr or unicode

The string to test.

Returns:
bool

True if URL scheme is supported for download (HTTP, HTTPS, FTP); False otherwise.

clear_download_cache(urls=None)[source]

Clears the data file cache by deleting the local file(s).

Parameters:
urlslist[str or unicode], optional

If given, a list of URLs to delete from the cache. Defaults to None, which deletes all files/URLs from the cache.

Returns:
None