Learn Fundamentals of Python

Python is one of the best programming languages for Network Engineers and demanding which will take their career a step ahead in networking field.

Given below are few topics on which we are going to discuss about:-

● Python Comparison Lists and Tuples

● Python Comparison Operators

● Major comparison between a list and a Tuple

● Lists in lists

● Python List Methods

● Commenting Python Code

● How to wrap long lines in Python?

Python Comparison Operators

Less than, greater than, equal to and not equal to for comparing the value on either side of them and decide the relation among them, they are also called Relational operators.

For example,

>>>a= “Python”

>>>a== ‘Python’

True

>>>a = 10

>>> (a==10) or (a!=5)

True

>>> (a==10) and (a!=5)

False

Major comparison between a list and a Tuple

Both tuples and lists are sequence data types that can store a collection of items. You can also access any item by its index and each item stored in a tuple or a list can be of any data type.

The main difference between lists and a tuples is that fact that lists are mutable (we can add delete, overwrite, existing elements) whereas tuples are immutable.

Lists in lists

A list is created by placing all the items (elements) inside a square bracket [], separated by commas. It can have any number of items and they may be of various types (string, float, integer, etc). Also, a list can ever have another list as an item.

>>> hostnames = [‘cisco-r1’,’cisco-r2’]

>>> type(hostnames)

>>> IPs = [‘1.1.1.1’,’1.1.1.2’]

>>>type(IPs)

>>>

>>>Devices = [hostnames, IPs]

>>>Devices

[[‘cisco-r1’,’cisco-r2’], [‘1.1.1.11’,’1.1.1.2’]]

>>>

>>>Devices[0] [‘cisco-r1’,’cisco-r2’]

>>>Devices[1] [‘1.1.1.11’,’1.1.1.2’]

>>>Devices[1][1]

‘1.1.1.2’

>>>Devices[0][0]

‘cisco-r1’

Python List Methods

 >>>hostnames.append(IPs)

>>>hostnames

[‘cisco-r1’,’cisco-r2’], [‘1.1.1.11’,’1.1.1.2’]]

 >>>hostnames = [‘cisco-r1’,’cisco-r2’]

>>> IPs = [‘1.1.1.11’,’1.1.1.2’]

>>>hostnames.extend(IPs)

>>>hostnames

[‘cisco-r1’,’cisco-r2’], [‘1.1.1.11’,’1.1.1.2’]

 >>>hostnames = [‘cisco-r1’,’cisco-r2’]

>>>hostnames +=IPs

>>>hostnames

[‘cisco-r1’,’cisco-r2’], [‘1.1.1.11’,’1.1.1.2’]

 Commenting Python Code

Commenting your code helps explain your thought process, and helps you and other to understand later on the intension of your code. It is seen as good practice for developers and is an important part of an individual workflow. Without comments, things can get confusing, real fast.

Example-

>>> #Defining List variable

… Var_List = [“hello”, “friends”]

>>> #Defining Tuple Variable

… Var_Tuple = (“Welcome to the”, “Python”, “Course”)

>>> #Here are we are using tuples concatenation along with converting list to tuples

… Var_Tuple_addition = tuple(var_list) +Var_Tuple

>>>Var_Tuple_addition

(‘hello’, ‘friends’, ‘Welcome to the’, ‘Python’, ‘Course’)

How to wrap long lines in Python?

The preferred way of wrapping long lines is by using Python’s implied lines continuation inside parentheses, brackets and braces, sometimes using a backlash look better. Make sure to indent the continued line appropriately.

Examples of parenthesized line break:

>>>list (“Hello”)

[‘H’, ‘e’, ‘l’, ‘l’, ‘o’]

>>>list (

… “Hello”

… “Friends”

… )

[‘H’, ‘e’, ‘l’, ‘l’, ‘o’, ‘F’, ‘r’, ‘i’, ‘e’, ‘n’, ‘d’, ‘s’]

 Example of back-slashes line breaks:

>>>print ( “Hello Friends \

… Welcome to Python \

… World”

… )

Hello Friends Welcome to Python World

>>> a = 1 + 2 \

… + 3+ 4 \

… + 5

>>> a

15