Range

Returns true if this range can be satisfied by the resource with the given byte length.

If there is only one range, and if it is satisfiable by the given length, then return a (begin, end) non-inclusive range of bytes to serve. Otherwise return None

If length is None (unknown length), then the resulting range may be (begin, None), meaning it should be served from that point. If it's a range with a fixed endpoint we won't know if it is satisfiable, so this will return None.

Works like range_for_length; returns None or a ContentRange object

You can use it like:

response.content_range = req.range.content_range(response.content_length)

Though it's still up to you to actually serve that content range!

Parse the header; may return None if header is invalid

Parse a Range header into (bytes, list_of_ranges). Note that the ranges are inclusive (like in HTTP, not like in Python typically).

Will return None if the header is invalid

Takes the output of parse_bytes and turns it into a header

Converts the list-of-ranges from parse_bytes() to a Python-style list of ranges (non-inclusive end points)

In the list of ranges, the last item can be None to indicate that it should go to the end of the file, and the first item can be negative to indicate that it should start from an offset from the end. If you give a length then this will not occur (negative numbers and offsets will be resolved).

If length is given, and any range is not value, then None is returned.

Converts a Python-style list of ranges to what serialize_bytes expects.

This is the inverse of bytes_to_python_ranges