Python Training and Exercises

Getting version of Python

>>>import sys

>>>print (sys.version)
3.5.2 (default, Sep 14 2017, 22:51:06) 

Different ways to assign value to variables

					
>>>a = 10

>>>a, b = 10, 20

>>>a = b = c = 10

>>>a, b = 10, "hello"


'''
Note 1:  a= 10 and a= '10' are not same. In the first command type of “a“ is integer and in the second “a” is a string

Note 2: You can use single quotes or double quotes or triple quotes to create strings. There is no difference in the functionality of single quote and double quote in python 
'''

>>> a = 'hello'

>>> b = 'hello world'

>>> c = "hello"

>>> d = "hello world"

'''
You can use three single quotes or three double quotes to create a string with multiple lines
'''

 >>> a ='''
... Interface eth0 is up
... IP is 192.168.1.1
... Mac is 00:11:22:33:44:55 
'''
>>> 

>>> b = """
... Interface eth0 is up
... IP is 192.168.1.1
... Mac is 00:11:22:33:44:55
"""

Getting input from keyboard/stdin

					
>>> a = input("enter something: ")

enter something: hello world

>>> print (a)
hello world

>>> b = int(input("enter a number: "))

enter a number: 100

>>> print (b)
100

Different ways of using print function

					
>>> a = 10
>>> b="hello"

>>> print (a)
10

>>> print (a,b)
10 hello

>>> print ("a is",a)
a is 10

>>> print ("a is %d" %a)
a is 10
>>> 

>>> print ("a is %d b is %s" %(a,b))
a is 10 b is hello

>>> print ("b is  " + b)
b is hello

'''
Note: Concatenating with “+” will only work for strings
'''

>>> a = 10
>>> print ("a is " +a )
TypeError: Cannot convert 'int' object to str implicitly
>>> 

>>> print ("a is " +str (a))
a is 10


>>> print ("Interface "EthernetO" is up")
    print ("Interface "EthernetO" is up")
                               ^
SyntaxError: invalid syntax

>>> print ("Interface \"EthernetO\" is up")
Interface "EthernetO" is up

>>> print ("Interface 'EthernetO' is up")
Interface 'EthernetO' is up

>>> print ('Interface "EthernetO" is up')
Interface "EthernetO" is up

>>> print ('Interface 'EthernetO' is up')
  File "<stdin>", line 1
    print ('Interface 'EthernetO' is up')
                               ^
SyntaxError: invalid syntax

Checking the type of a variable using “type” function

					
>>> a, b = 10, "hello"

>>> type(a)
<class 'int'>

>>> type(b)
<class 'str'>

>>> c=10.2

>>> type(c)
<class 'float'>

>>> d = [10,20,30]

>>> type(d)
<class 'list'>

>>> e=(100,200,300)

>>> type(e)
<class 'tuple'>
>>> 

>>> type(print)
<class 'builtin_function_or_method'>


				

Using Python membership operators

>>> a= "hello world"

>>> 'e' in a
True

>>> 'ello' in a
True

>>> 'xy' in a
False

>>> 'e' not in a
False

>>> 'xy' not in a
True

Syntax of control statements: If ,else and elif

					
a, b, c = 10, 20, 30

if a == 10:
   	 print ("hello")

 
if a==10 and b <25:
  	 print ("hello")
 
if a==10 or b <25:
  	 print ("hello")

if a>10:
	print ("hello")
else:
	print ("hi")
 
 
if a <10:
	  print ("hello")
elif a>10:
	  print ("hello world")
else:
	  print ("hi")
	 

if a==10 and b<=30:
	print ("hello")
	if c < 50:
		print ("hello world")
	else:
		print ("hi")
 
 

Python Exercises

Next chapter: Python training : While loops, For loops and Range function