E.g. we have option format description string with 2 or 3 items value1 value2 [optional value]

s = "foo bar" # This is a valid example option string

s2 = "foo bar optional" # This is also, with one optional item

Usually we’d like to parse this so that non-existing options are set to None. Traditonally one does Python code like below:

# Try get extration and deletion
parts = s.split(" ")
value1 = parts[0]
value2 = parts[1]
if len(parts) >= 3:
    optional_value = parts[2]
else:
    optionanl_value = None

However, this looks little bit ugly, considering  if there would always be just two options one could write:

value1, value2 = s.split(" ")

When the number of optional options grow, the boiler-plate code starts annoy greatly.

I have been thinking how to write a split() code to parse options with non-existing items to be set None. Below is my approach for a string with total of 4 options of which any number can be optional.

parts = s.split(" ", 4) # Will raise exception if too many options 
parts += [None] * (4 - len(parts)) # Assume we can have max. 4 items. Fill in missing entries with None.
value1, value2, optional_value, optional_value2 = parts

Any ideas for something more elegant?

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I found this nice library from Denis Laprise. However, it had a bug with fragment extractor and lacked reconstruction possibilies. So I decided to make a new version.

Download urlparse.js version 0.2. thank you

Couple of examples:

var p = new Poly9.URLParser('http://user:password@poly9.com/pathname?arguments=1#fragment');
p.getHost() == 'poly9.com';
p.getProtocol() == 'http';
p.getPathname() == '/pathname';
p.getQuerystring() == 'arguments=1';
p.getFragment() == 'fragment';
p.getUsername() == 'user';
p.getPassword() == 'password';

var p = new Poly9.URLParser("http://localhost:8080/path);

p.setQuerystring("foo=bar");
p.setFragment("anchor");
p.setPort(7070);

var url = p.getURL() // http://localhost:7070/path?foo=bar#anchor