Equivalent of std::set

[Nicolas Fleury]

Hi,

I haven't work so much in python and I was wondering what python
programmers use for string collections, like an equivalent of C++
std::set. Do you use a dictionary with dummy values? Tuple/list? Is
there any other structure in some module with uniqueness ensured and
lookup optimised? I'm only interested in storing strings in that structure.

Thx for help

Nicolas

 

[anton muhin]

Hi,

I haven't work so much in python and I was wondering what python
programmers use for string collections, like an equivalent of C++
std::set. Do you use a dictionary with dummy values? Tuple/list? Is
there any other structure in some module with uniqueness ensured and
lookup optimised? I'm only interested in storing strings in that
structure.

Thx for help

Nicolas

Python 2.3 introduced Set type, in the former versions common idiom was
to use dictionaries with dummies IMHO.

anton.

 

[Stephen Horne]

Hi,

I haven't work so much in python and I was wondering what python
programmers use for string collections, like an equivalent of C++
std::set. Do you use a dictionary with dummy values? Tuple/list? Is
there any other structure in some module with uniqueness ensured and
lookup optimised? I'm only interested in storing strings in that structure.

Thx for help

Nicolas

A set type was introduced in Python 2.3...

http://www.python.org/doc/2.3/whatsnew/whatsnew23.html

http://www.python.org/doc/2.3/lib/module-sets.html

There are other ways, depending on what you are doing with the
strings, though.

For instance, although you can iterate a set, the iteration will not
necessarily be in order (I assume it uses hashing internally, probably
by using a dictionary internally). If you need to access the strings
in order (and there aren't too many of them) you can keep the items in
a sorted list, in which case the bisect module will probably be a big
help.