Python Snippets

DevNet Python Snippets refer to small, reusable pieces of Python code specifically designed for network automation and programmability within the Cisco DevNet ecosystem. These snippets typically showcase how to interact with Cisco platforms, devices, or APIs using Python scripts. They serve as practical examples and templates for developers looking to automate network configurations, retrieve device information, or perform various tasks programmatically. DevNet Python Snippets often leverage Cisco's Python libraries, such as the Cisco SDK or requests library for working with REST APIs like RESTCONF or NETCONF. These code snippets are valuable resources for DevNet developers, providing quick references and examples that accelerate the development of network automation solutions within the Cisco environment. They contribute to the collaborative and knowledge-sharing nature of the DevNet community, fostering efficiency and innovation in network programmability.

Lab:

""" MODULE Docstring: RSTFORUM DEVNET Python LAB SCRIPTS """
'==============================================================================='
# "print Welcome to RSTForum"
'==============================================================================='

print (“Welcome to RSTForum")

'==============================================================================='
# print (“Hello, World") and (“Welcome") one below the other
'==============================================================================='

print (“Hello, World"); print (“Welcome")

'==============================================================================='
# run a "test.py" script that was downloaded on computer by issuing following
# python -i test.py
'==============================================================================='

python –i test.py

'==============================================================================='
# Variables
'==============================================================================='

my_number = 5
my_number

'==============================================================================='
# function
'==============================================================================='

def my_function():
    print("Hello from a function")

my_function()

'==============================================================================='
# class
'==============================================================================='

class Myclass:
   x = 5
	
Myclass

'==============================================================================='
# object
'==============================================================================='

myobject = Myclass ()
myobject.x

'==============================================================================='
# Lines and indentation
'==============================================================================='

if True:
   print ("True“)
else:
    print ("False“)

'==============================================================================='
# quotation # comment strings
'==============================================================================='

'This is a comment'
" This is also a comment"
""" This is also a comment"""

'==============================================================================='
# comment strings
#example 1
'==============================================================================='

#This is a comment
'Welcome to RSTForum'

'==============================================================================='
#example 2
'==============================================================================='

print "Hello, Python!" #This is a comment

'==============================================================================='
#example 3
'==============================================================================='

"""
This is a comment
"""
print("Hello, RSTForum")

'==============================================================================='
# Waiting for user input
#example 1
'==============================================================================='

input ("\n\nPress the enter key to exit.")

'==============================================================================='
# run a "wait.py" script that was downloaded on computer by issuing following
# python -i wait.py
'==============================================================================='

python –i wait.py

'==============================================================================='
# multiple Statements on single line
'==============================================================================='

import sys; x='RST'; sys.stdout.write(x +'\n')

'==============================================================================='
#Python Variables examples
#example 1
'==============================================================================='

x = 1
print (x)

'==============================================================================='
#example 2
'==============================================================================='

name, weight = "aliya" , 42.8
print (name, weight)

'==============================================================================='
#example 3
'==============================================================================='

name = "ash"
weight = 48.5
name; weight

'==============================================================================='
#example 4
'==============================================================================='

a = b = c = 1
a, b, c

'==============================================================================='
#example 5
'==============================================================================='

a = b = c = 1
a; b; c

'==============================================================================='
# Python Output Variables Examples
#example 1
'==============================================================================='

x = "RSTForum"
print ("Welcome to " + x)

'==============================================================================='
#example 1
'==============================================================================='

x = 5
y = 10
print(x + y)

'==============================================================================='
#example 2
'==============================================================================='

x = "Python is "
y = "Great"
z =  x + y
print(z)

'==============================================================================='
#example 3 TypeError: unsupported operand type(s) for +: 'int' and 'str' 
'==============================================================================='

x = 5 ; y = “RST"
print(x+y)
#should return "error TypeError:unsupported operand type(s) for +: 'int' and 'str'

'==============================================================================='
#Python Global Variables
#example 1
'==============================================================================='

x = "RSTForum"
def myfunction():
    print ("Welcome to " + x)

myfunction()

'==============================================================================='
#example 2
'==============================================================================='

x = “Python“
	
def myfunction():
    x = “RSTForum"
    print(“Welcome to " + x)

myfunction()
print(“Welcome to " + x)

'==============================================================================='
#example 3
'==============================================================================='

Welcome to RSTForum
print("Welcome to " + x)

'==============================================================================='
#Python Global Variables inside a 
#example 1
'==============================================================================='

def myfunction():
    global x
    x = "RSTForum“

myfunction()
print ("Welcome to " + x)

'==============================================================================='
#example 2
'==============================================================================='

x = “RSTForum“
def myfunction():
    global x
    x = “Python“

myfunction()
print(“Welcome to " + x)

'==============================================================================='
#Python Data Type
#string
'==============================================================================='

x = "Hello RSTForum"
print(x) ; print(type(x)) 

'==============================================================================='
#integer
'==============================================================================='

x = 5
print(x) ; print(type(x)) 

'==============================================================================='
#float
'==============================================================================='

x = 5.8
print(x) ; print(type(x)) 

'==============================================================================='
#complex
'==============================================================================='

x = 5j
print(x) ; print(type(x))

'==============================================================================='
#list
'==============================================================================='

x = [“jay", “veeru", “gabbar"]
print(x) ; print(type(x)) 

'==============================================================================='
#Tuple
'==============================================================================='

x = (“jay", “veeru", “gabbar“)
print(x) ; print(type(x)) 

'==============================================================================='
#range
'==============================================================================='

x = range(5)
print(x) ; print(type(x)) 

'==============================================================================='
#dictionary
'==============================================================================='

x = {"name" : “Rohish", "age" : 31}
print(x) ; print(type(x)) 

'==============================================================================='
#set
'==============================================================================='

x = {“jay", “veeru", “gabbar"}
print(x) ; print(type(x)) 

'==============================================================================='
#frozenset
'==============================================================================='

x = frozenset({“jay", “veeru", “gabbar"})
print(x) ; print(type(x)) 

'==============================================================================='
#boolean
'==============================================================================='

x = True
print(x) ; print(type(x))

'==============================================================================='
#bytes
'==============================================================================='

x = b“RSTForum"
print(x) ; print(type(x))

'==============================================================================='
#bytearray
'==============================================================================='

x = bytearray(5)
print(x) ; print(type(x))

'==============================================================================='
#Memoryview
'==============================================================================='

x = memoryview(bytes(5))
print(x) ; print(type(x)) 

'==============================================================================='
#Python Numbers Type Conversion
#example 1
'==============================================================================='

x = 1    # int
y = 2.8  # float

a = float(x)
b = int(y)
c = complex(x)

print(a);print(b);print(c);print(type(a)); print(type(b));print(type(c))

'==============================================================================='
#Python Random Numbers
#example 1
'==============================================================================='

import random
print (random.randrange (1, 10))

'==============================================================================='
#Python playing around with Strings 
#example 2
#String: "Hello, World!"
#To get the character at position 4 
#(first character has the position 0)
'==============================================================================='

a = "Hello, World!"
print(a[4])

'==============================================================================='
#example 3
#To get the character from position 2 to position 5:
'==============================================================================='

a = "Hello, World!"
print(a[2:5])

'==============================================================================='
#example 4
#To Get the characters from position 4 to position 1, 
#starting the count from the end of the string
'==============================================================================='

a = "Hello, World!"
print(a[-4:-1])

'==============================================================================='
#example 5
#To Get the length of a string use the len() function
'==============================================================================='

a = "Hello, World!"
print(len(a))
13

'==============================================================================='
#example 6
#String: “   Hey RSTForum   "
#The strip() method removes any whitespace from the beginning or the end: 
'==============================================================================='

b = “     Hey RSTForum     "
print(b.strip())

'==============================================================================='
#example 7
# The lower() function returns the string in lower case:
'==============================================================================='

"WhO wRoTe THIs? " .lower() 

'==============================================================================='
#example 8
#The upper() function returns the string in upper case:
'==============================================================================='

b = "Hey RSTForum"
print(b.upper())

'==============================================================================='
#example 9
#The replace() replaces a string with another string:
'==============================================================================='

b = "Hey RSTForum"
print(b.replace(“e", “o"))

'==============================================================================='
#example 10
#The split() splits a string into 2 parts: if it finds ‘” , “
'==============================================================================='

a = "Hello, RSTForum!"
print(a.split(",")) 

'==============================================================================='
#example 11
#Merge variable x with variable y into variable z:
'==============================================================================='

x = “Welcome" ; y = “RSTForum“ ; z = x + y
print(z)

'==============================================================================='
#example 12
#To add a space between them, add a " “ :
'==============================================================================='

x = “Welcome" ; y = “RSTForum“ 
z = x +“ “+ y
print(z)

'==============================================================================='
#example 13
#To add strings
'==============================================================================='

“RST” + “Forum”

'==============================================================================='
#example 14
#display a string twice
'==============================================================================='

“RST” * 2

'==============================================================================='
#example 15
#The format() helps insert number into the string:
'==============================================================================='

age = 21 ; txt="My name is Lee, and I am {}"
print(txt.format(age))

'==============================================================================='
#example 16
#Insert multiple items in a string:
'==============================================================================='

name = “Lee” ; age = 21
txt="My name is {} , and I am {}"
print(txt.format(name, age))

'==============================================================================='
#example 17
#new way to Insert items in a string:
'==============================================================================='

“Welcome to {} “.format (“RSTForum“)

'==============================================================================='
#example 18
#The join() joins string separated by ‘” , “ into one string
'==============================================================================='

",".join(['a','b','c'])
'a,b,c'

'==============================================================================='
#Escape Characters
#Single Quote: \'
'==============================================================================='

txt = 'It\'s alright.' ; print(txt)

'==============================================================================='
#Escape Characters
#Slash: \\
'==============================================================================='

txt = 'Five \\ Two' ; print(txt)

'==============================================================================='
#Escape Characters
#New Line: \n
'==============================================================================='

txt = 'RST \n Forum' ; print(txt)

'==============================================================================='
#Escape Characters
#Tab: \t
'==============================================================================='

txt = 'RST\tForum.' ; print(txt)

'==============================================================================='
#Escape Characters
#Backspace: \b
'==============================================================================='

txt = 'RST \bForum.' ; print(txt)

'==============================================================================='
#Arithmetic Operators
#addition
'==============================================================================='

x=4 ; y=2 ; z=x+y ; print(z)

'==============================================================================='
#Arithmetic Operators
#substraction
'==============================================================================='

x=4 ; y=2 ; z=x-y ; print(z)

'==============================================================================='
#Arithmetic Operators
#Multiplication
'==============================================================================='

x=4 ; y=2 ; z=x*y ; print(z)

'==============================================================================='
#Arithmetic Operators
#Division
'==============================================================================='

x=4 ; y=2 ; z=x/y ; print(z)

'==============================================================================='
#Arithmetic Operators
#Modulus
'==============================================================================='

x=4 ; y=2 ; z=x%y ; print(z)

'==============================================================================='
#Arithmetic Operators
#exponential
'==============================================================================='

x=4 ; y=2 ; z=x**y ; print(z)

'==============================================================================='
#Arithmetic Operators
#floor division
'==============================================================================='

x=4 ; y=2 ; z=x//y ; print(z)

'==============================================================================='
#Comparison Operators
#Equal x==y
'==============================================================================='

x=4 ; y=2 ; print(x == y)	       

'==============================================================================='
#Comparison Operators
#Not Equal x!=y
'==============================================================================='

x=4 ; y=2 ; print(x!=y)

'==============================================================================='
#Comparison Operators
#Greater Than x>y
'==============================================================================='

x=4 ; y=2 ; print(x>y)      

'==============================================================================='
#Comparison Operators
#Greater Than x<y
'==============================================================================='

x=4 ; y=2 ; print(x<y)

'==============================================================================='
#Comparison Operators
#Less Than x<y
'==============================================================================='

x=4 ; y=2 ; print(x>=y)

'==============================================================================='
#Comparison Operators
# Greater Than Equal To x>=y
'==============================================================================='

x=4 ; y=2 ; print(x>=y)       

'==============================================================================='
#Comparison Operators
# Less Than Equal To x<=y
'==============================================================================='

x=4 ; y=2 ; print(x<=y)

'==============================================================================='
#Comparison Operators if if else loop
'==============================================================================='

x=4
if x<4:print(“x is less than four”)
elif x==4:print(“x is equal to four”)
else:print(“x is greater than four”)

'==============================================================================='
# Logical and Identity Operators
# and	x < 5 and  x < 10
'==============================================================================='

x=5 ; print (x<5 and x<10)

'==============================================================================='
# Logical and Identity Operators
# or	x < 5 or  x < 4
'==============================================================================='

x=5 ; print (x<5 or x<4)

'==============================================================================='
# Logical and Identity Operators
# and	not(x<5 and x<10))
'==============================================================================='

x=4 ; print(not(x<5 and x<10))

'==============================================================================='
# Logical and Identity Operators
# and	x is y; x==y
'==============================================================================='

x=["cat", "dog"] ; y=["cat", "dog"] ; z=x
print(x is z)
print(x is y)  #False, as x and y are 2 different objects
print(x == y)
print("dog" in x)
print("rat" not in x)

'==============================================================================='
# Functions
# example 1
'==============================================================================='

def my_function():print(“RSTForum")

my_function()

'==============================================================================='
# Functions
# example 2
'==============================================================================='

def function(name):
  print(name + ” “ + “RSTForum")

function(“H!")
function(“Hello")

'==============================================================================='
# Functions
# example 3
'==============================================================================='

def function(name1, name2):
  print(name1 + ” “ + name2)

function(“Hi“ , “Hello")

'==============================================================================='
# Functions with Arbitrary Arguments(*args): 
#if we don't know how many arguments will be passed in our function, add a * :
# example 4
'==============================================================================='

def function(*day):
  print("Today is " + day[2])

function(“Monday", "Tuesday", “Wednesday")

'==============================================================================='
# Functions with Arbitrary Arguments(*args):
# Passing a List as an Argument:
# example 5
'==============================================================================='

def my_function(items):
  for x in items:
    print(x)

comp = [“CPU", “RAM", “SSD"]
vehicle = [“Cycle", “Car", “Bus"]
my_function(comp) 
my_function(vehicle)

'==============================================================================='
# Functions
# example 6
'==============================================================================='

def add(num1, num2):
     result = num1 + num2
     return result

add(3, 5)

'==============================================================================='
# A list is a collection which is ordered and changeable. 
# lists are written with square brackets.
# example 1
'==============================================================================='

x = ['a', 5, 16.4]
x[2]

'==============================================================================='
# List
# example 2
'==============================================================================='

x = ['a', 5, 16.4]
x[2] =20.5
x

'==============================================================================='
# List
# example 3
'==============================================================================='

x = ['a', 5, 20.5]
x.append (“new”)
x

'==============================================================================='
# List
# example 4
'==============================================================================='

x = ['a', 5, 20.5]
x.insert (1, “new”)
x

'==============================================================================='
# List
# example 5
'==============================================================================='

x = ['a','new', 5, 20.5]
x.remove ('new')
x

'==============================================================================='
# List
# example 6
'==============================================================================='

x = ['a', 5, 20.5]
del x[0] 
x

'==============================================================================='
# List
# example 7
'==============================================================================='

x = ['a', 5, 20.5]
y=x.copy()
y

'==============================================================================='
# Tuples
# example 1
'==============================================================================='

x = ('a', 5, 16.4)
x[2]

'==============================================================================='
# Dictionary: Python dictionaries are written with curly brackets,
# They have keys and values.
# example 1
'==============================================================================='

mydict = {“name“: “RSTForum“, “since“: “1997“} 
mydict

'==============================================================================='
# Dictionary:
# example 2
'==============================================================================='

mydict = {“name“: “RSTForum“, “since“: “1997“} 
mydict[“since”]

'==============================================================================='
# Dictionary:
# example 3
'==============================================================================='

mydict = {“name“: “RSTForum“, “since“: “1997“}
x = mydict[“since"]
print(x)

'==============================================================================='
# Dictionary:
# example 4
'==============================================================================='

mydict = {“name“: “RSTForum“, “since“: “1997“}
x=mydict["since"] =2020
mydict

'==============================================================================='
# Dictionary:
# example 5
'==============================================================================='

mydict = {“name“: “RSTForum“, “since“: “2020“}
y=mydict.get("name")
y

'==============================================================================='
# Dictionary:
# example 6
'==============================================================================='

if “since" in mydict:
   print("Yes, ‘since' is a keys in our dictionary")

'==============================================================================='
# Dictionary: You can loop through a dictionary by using a for loop:
# Print all key names in the dictionary, one by one:
'==============================================================================='

mydict = {“name“: “RSTForum“, “since“: “1997“} 
for x in mydict:  print(x)

'==============================================================================='
# Dictionary: You can loop through a dictionary by using a for loop:
# Print all values in the dictionary, one by one:
'==============================================================================='

mydict = {“name“: “RSTForum“, “since“: “1997“}
for x in mydict:  print(mydict[x])

'==============================================================================='
# Dictionary: You can loop through a dictionary by using a for loop:
# we can also use the value() method to return values of dict:
'==============================================================================='

mydict = {“name“: “RSTForum“, “since“: “1997“}
for x in mydict.values():  print(x)

'==============================================================================='
# Dictionary: You can loop through a dictionary by using a for loop:
# Print the number of items in the dictionary:
'==============================================================================='

mydict = {“name“: “RSTForum“, “since“: “1997“}
len(mydict)

'==============================================================================='
# While Loop: Statements keep executing till condition is true:
# example 1
'==============================================================================='

i = 1 
while i < 4: 
   print(i)
   i += 1

'==============================================================================='
# While Loop:
# example 2
'==============================================================================='

i = 1
while i < 6:
    print(i)
    if (i == 2):
       break
    i += 1

'==============================================================================='
# While Loop:
# example 3
'==============================================================================='

i = 1
while i < 3:
    print(i)
    i += 1
else:
     print("i is no longer less than 3")

'==============================================================================='
# While Loop:
# example 4
'==============================================================================='

from time import sleep
while True:
     try:
         print("Polling.")
         sleep(1)
     except KeyboardInterrupt:
         break

'==============================================================================='
# For Loop:
# example 1
'==============================================================================='

for i in range (3): 
    print (i)

'==============================================================================='
# For Loop:
# example 2
'==============================================================================='

names = [“RST”, “Forum”]
for x in names:
    print(x)

'==============================================================================='
# For Loop:
# example 3
'==============================================================================='

list = [ ( "apple", 2 ) ,  ( "banana“ , 3 ) ]
for fruit in list:
    print(fruit)

'==============================================================================='
# For Loop:
# example 4
'==============================================================================='

dict = { "apple“ : 2  ,  "banana“ : 3 }
for x,y in dict.items(): # using items functon
    print(x,y)

'==============================================================================='
# For Loop:
# example 5
'==============================================================================='

dict = { "apple“ : 2  ,  "banana“ : 3 }
for x, y in dict.items(): 
  print(y)

'==============================================================================='
# For Loop:
# example 6
'==============================================================================='

dict = { "apple“ : 2  ,  "banana“ : 3 }
for x in dict.values(): # using values functon
    print(x)

'==============================================================================='
''' Thank You From RSTForum '''
'==============================================================================='