Python 2 Vs 3

Python 2	Python 3
input() may store as int, string raw_input() stores str always	input() function was fixed in Python 3 so that it always stores the user inputs as str
print "Hi" print("Hi")	print("Hi")
3/2 ==> floor(1.5) => 1 (defaults to floor), return int	3/2 ==> 1.5
Strings default stores as Ascii	Strings default stores as unicode Unicode is a superset of ASCII and hence, can encode more characters including foreign ones.
sorted(employees.items(), key=lambda(x,y): y['age'])	sorted(employees.items(), key=lambda x: x[1]['age'])
	AsyncIO
	Fstrings
	It is recommended to use __future__ imports it if you are planning Python 3.x support for your code
xrange() - Lazy evaluation	range() - Lazy evaluation
except NameError, err:	except NameError as err:
my_generator = (letter for letter in 'abcdefg') next(my_generator) my_generator.next()	my_generator = (letter for letter in 'abcdefg') next(my_generator)
print 'Python', python_version() i = 1 print 'before: i =', i print 'comprehension: ', [i for i in range(5)] print 'after: i =', i Python 2.7.6 before: i = 1 comprehension: [0, 1, 2, 3, 4] after: i = 4	Python 3.x for-loop variables don’t leak into the global namespace anymore! print ('Python', python_version()) i = 1 print 'before: i =', i print 'comprehension: ', [i for i in range(5)] print 'after: i =', i Python 3.4.1 before: i = 1 comprehension: [0, 1, 2, 3, 4] after: i = 1
print range(3) print type(range(3)) [0, 1, 2] <type 'list'>	print range(3) print type(range(3)) print(list(range(3))) range(0, 3) <class 'range'> [0, 1, 2]
round(15.5) # 16.0 round(16.5) # 17.0	Bankers rounding round(15.5) # 16 round(16.5) # 16

Learning For While loops in Python

#!/usr/local/bin/python2.7

'''
    Learning For/While loops in Python
    File name: for_while_loop_python.py
    Author: Prabhath Kota
    Date: June 22, 2018
    Python Version: 2.7
'''

'''
Topics:
For loop
While loop
range
break
continue
enumerate
'''

print '----------------For loop---------------------'
freedom_fighters = ["Lala Lajipati Rai", "Dadabhai Naoroji", "Rajendra Prasad", "Sarojini Naidu", "Dadabhai Naoroji", "Lal Bahadur Shastri"]
print freedom_fighters
for each in freedom_fighters:
print each

print '----------------For loop Break---------------------'
print freedom_fighters
#Print only first 4 elements using Break statement
#Enumerate will get you index of the element as well - starting from 0
#enumerate(freedom_fighters) will start the index from 0
#enumerate(freedom_fighters, 1) will start the index from 1
for index,each in enumerate(freedom_fighters, 1):
print index, each
if index == 4:
break
print '----------------For loop Continue---------------------'
print freedom_fighters
#Print only even elements from the list
for index,each in enumerate(freedom_fighters, 1):
if index % 2 == 1: #Odd elements
continue
else: #Even Elements
print index, each

print '----------------For loop Range---------------' 
squares = []
print range(1,10)
for x in range(0,10):
squares.append(x**2)
print (squares)

print '----------------While loop---------------'
#Try to avoild While loops, use only unless otherwise reequired
#If you sometimes don't handle it, it may end up in infinite loop
i = 0
squares = []
while(i < 10):
squares.append(i**2)
i += 1
print squares

Output:

----------------For loop---------------------

['Lala Lajipati Rai', 'Dadabhai Naoroji', 'Rajendra Prasad', 'Sarojini Naidu', 'Dadabhai Naoroji', 'Lal Bahadur Shastri']

Lala Lajipati Rai

Dadabhai Naoroji

Rajendra Prasad

Sarojini Naidu

Dadabhai Naoroji

Lal Bahadur Shastri

----------------For loop Break---------------------

['Lala Lajipati Rai', 'Dadabhai Naoroji', 'Rajendra Prasad', 'Sarojini Naidu', 'Dadabhai Naoroji', 'Lal Bahadur Shastri']

1 Lala Lajipati Rai

2 Dadabhai Naoroji

3 Rajendra Prasad

4 Sarojini Naidu

----------------For loop Continue---------------------

['Lala Lajipati Rai', 'Dadabhai Naoroji', 'Rajendra Prasad', 'Sarojini Naidu', 'Dadabhai Naoroji', 'Lal Bahadur Shastri']

2 Dadabhai Naoroji

4 Sarojini Naidu

6 Lal Bahadur Shastri

----------------For loop Range---------------

[1, 2, 3, 4, 5, 6, 7, 8, 9]

[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

----------------While loop---------------

[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

[Finished in 0.2s]