reverse-lookup

I'm building a web app that tracks what library books a person checks out. I have the following models: class Person(models.Model): name = models.CharField(max_length=100) def __unicode__(self): return self.name class Book(models.Model): name = models.CharField(max_length=100) person = models.ForeignKey(Person) checkout_date = models.DateTimeField('checkout date') def __unicode__(self): return self.name On the Admin's "change list" page for Person, I would like to show what books that person has. Is this something that can be done? If so, how? admin.py class BookAdmin(admin.ModelAdmin): list

Is there any way to do a reverse lookup using python, to check the list of websites sharing the same IP address in a shared hosting. Some web sites offer a tool for this purpose . DNSPython Technically, you can use DNSPython to do a reverse lookup. Pip install it $ pip install dnspython Then do your reverse query: >>> from dns import resolver >>> from dns import reversename >>> addr = reversename.from_address("74.125.227.114") >>> resolver.query(addr, "PTR")[0] <DNS IN PTR rdata: dfw06s16-in-f18.1e100.net.> socket.gethostbyaddr You can also use socket.gethostbyaddr >>> import socket >>> name,

Python's list type has an index() method that takes one parameter and returns the index of the first item in the list matching the parameter. For instance: >>> some_list = ["apple", "pear", "banana", "grape"] >>> some_list.index("pear") 1 >>> some_list.index("grape") 3 Is there a graceful (idiomatic) way to extend this to lists of complex objects, like tuples? Ideally, I'd like to be able to do something like this: >>> tuple_list = [("pineapple", 5), ("cherry", 7), ("kumquat", 3), ("plum", 11)] >>> some_list.getIndexOfTuple(1, 7) 1 >>> some_list.getIndexOfTuple(0, "kumquat") 2 getIndexOfTuple(

I have data that is organized in kind of a "key-key" format, rather than "key-value". It's like a HashMap, but I will need O(1) lookup in both directions. Is there a name for this type of data structure, and is anything like this included in Java's standard libraries? (or maybe Apache Commons?) I could write my own class that basically uses two mirrored Maps, but I'd rather not reinvent the wheel (if this already exists but I'm just not searching for the right term). uckelman There is no such class in the Java API. The Apache Commons class you want is going to be one of the implementations of