Python Programming for beginners. Pt 4 – Dictionaries Concept

image source : python shell (screenshot)

By : Bijay Acharya / studentvideotutorial

Well, welcome to Part 4. Here, I’ll give you the basic concepts on Dictionaries when it comes to programming in Python.
– The Python dictionary data structure provides a hash table that can store any number of Python objects. The dictionary consists of pairs of items that contain a KEY and VALUE. 

– When constructing a dictionary, each KEY is separated from a value by a colon (:), and we separate items by Commas (,).

The complete Code looks like this [Note: Explanation of each line of code is provided below the code]:

>>> services = {‘ftp’:21, ‘ssh’:22, ‘smtp’:25, ‘http’:80}

>>> services.keys()

[‘ftp’, ‘http’, ‘smtp’, ‘ssh’]

>>> services.items()

[(‘ftp’, 21), (‘http’, 80), (‘smtp’, 25), (‘ssh’, 22)]

>>> services.has_key(‘ftp’)

True

>>> services[‘ftp’]

21

>>> print “[+] Found vuln with FTP on port “+str(services[‘ftp’])

[+] Found vuln with FTP on port 21

 EXPLANATION:

Let’s see first line of code:

services = {‘ftp’:21, ‘ssh’:22, ‘smtp’:25, ‘http’:80}  – Here, we’re creating a dictionary named ‘services‘, and the KEYs are ftp,ssh,smtp,http . . . which are separated from VALUEs by colons. [Note: values are 21,22,25,80] . . . And, these four items are separated by commas.

The second line of code:

services.keys()  – .keys() is method that will return all the keys in dictionary.

The third line of code:

services.items()  – .items() is method that will return the entire list of items in dictionary.

The fourth line of code:

services.has_key(‘ftp’)  – it’s a kind of question like Has Key FTP ? . . . If yes, then the value returns TRUE.

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Well, this was about creating a Dictionary in Python. References: Violent Python PDF, Cybrary Study Materials and Python.Org