collections-plus 0.1.1

A Python library to implement various data structures.

collections-plus

A Python library implementing various data structures.

Installation

You can install this package using pip:

pip install collections-plus

and import the library with

import collections_plus

Please note that this code is in a pre-alpha state and will likely contain bugs.

Basic Usage and Examples

Currently, collections-plus supports Linked Lists. Briefly speaking, a linked list is a data structure where each node stores both a value and a pointer to the next node. This makes insertions and removals near the start very fast, at the expense of slower indexing.

To create a Linked List, first import the class:

from collections_plus import LinkedList

Then, you can create a Linked List like so:

my_llist = LinkedList(1, 2, 3, "pi", 4)

Or, if you have an existing list, you can unpack it:

sample_list = [1, 4, 3, 4]
sample_ll = LinkedList(*sample_list)

LinkedLists support most things you can do with a good old Python list. For instance, you can index into, mutate, and delete nodes (unfortunately, slicing is not implemented as of version 0.1.0):

indexed = my_llist[1] # indexed = 2
my_llist[2] = "approx pi" # sets value to "approx pi"
del my_llist[1] 
print(my_llist) # LinkedList(1, "approx pi", "pi" 4)

Notably, you can pop, append, and insert:

sample_ll.pop() # returns 1
print(sample_ll) # LinkedList(4, 3, 4)
sample_ll.pop(2) # returns 4
print(sample_ll) # LinkedList(4, 3)
sample_ll.append("game")
print(sample_ll) # LinkedList(4, 3, 'game')
sample_ll.insert(0, "lost")
print(sample_ll) # LinkedList('lost', 4, 3, 'game')

Generally, pop, append, and insert will most often be used to implement a FILO or FIFO queue. Please note that insert(-1, val) will also be slower than append(val) because of the linked list structure.

This package also supports a variety of other functions that work very similar to their equivalents for default lists:

• len(llist)
• llist.extend(other)
• llist.count(val)
• llist.index(val)
• llist.remove(val)
• llist.copy()
• Binary comparators ==, !=, <, <=, >, >=
• Operators + and *