This document provides an introduction to Python for high school programmers. It covers background information on Python, key concepts like data types and operators, and basics of the language like variables, collections, control flow, and object-oriented programming. Code examples are included to demonstrate various features. The presentation aims to get students started with Python and provide an overview of what it can do.

1. Python for High
School Programmers
April 06, 2013
Sivasubramaniam Arunachalam @sivaa_in

2. It’s me!
• Application Developer
• Web/Enterprise/Middleware/B2B
• Java/Java EE, Python/Django
• 2002
• Technical Consultant
• Process Mentor
• Speaker

3. It’s about you!
Have you written a code recently?
Yes / No / Never
It doesn’t matter!

4. Agenda
• Background
• Concepts
• Basics
• Demo

5. for / else
for ( int i = 0; i < 10; i++ ) {
……
} else {
……
}

6. Back in 1989

7. Guido van Rossum
http://www.python.org/~guido/images/guido91.gif

8. https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcRsHF89zT2tSdsm45hFYDaJPocfpwIM_Eh76pjKbTzZI2dxArWa

9. http://upload.wikimedia.org/wikipedia/en/9/9a/CompleteFlyingCircusDVD.jpg

10. High Level Language

11. Dynamic / Scripting
Language

12. Zen of Python
• Beautiful is better than ugly.
• Explicit is better than implicit.
• Simple is better than complex.
• Complex is better than complicated.
• Flat is better than nested.
• Sparse is better than dense.
• Readability counts.
• Special cases aren't special enough to break the rules.
• Although practicality beats purity.
• Errors should never pass silently.
• Unless explicitly silenced.
• In the face of ambiguity, refuse the temptation to guess.
• There should be one-- and preferably only one --obvious way to do it.
• Although that way may not be obvious at first unless you're Dutch.
• Now is better than never.
• Although never is often better than *right* now.
• If the implementation is hard to explain, it's a bad idea.
• If the implementation is easy to explain, it may be a good idea.
• Namespaces are one honking great idea -- let's do more of those!

13. Why?

14. Clean / Clear Syntax

15. Less Key Words
31

16. Portable
• Servers / Desktops / Mobile Devices / Raspberry Pi
• Windows/Unix/Linux/Mac
• Pre-installed in Mac and Linux

17. Multi-Language
Support
• CPython
• Jython
• IronPython

18. Multi-Paradigm
• Functional / Procedural / Object Oriented

19. Easy to Learn

20. Highly Readable

21. No Variable Declaration

22. More Productivity
...the lines of Python code were 10% of the equivalent C++ code. - Greg Stein

23. Batteries Included

24. Open Source

25. Where I can use?
• Stand-Alone Application
• Desktop/GUI Application
• Web Application
• XML Processing
• Database Application
• Network Application
• Scientific Application
• Gaming
• Robotics

26. Some One using it?

28. Hello World!

29. Installation / Tools
• Interpreter
• Script Editor

30. . py
.pyc
.pyo
.pyd

31. Optimized Code
• Faster Execution
• Less CPU Cycles

32. Increment ‘i’ by 1
i++
i=i+1
ADD #1,A1 [A1] ← [A1] + 1

33. Machine Instructions
/
Line of Code (LoC)

34. Assembly Language 1-2
System Languages 3-7
Scripting Languages 100 - 1K

35. Current Versions
2.7.3 & 3.3.0

36. The Prompt
>>>

37. How to run?
C:> python my_program.py

38. Let’s Start
• Start / Exit
• Simple print
• Zen of Python
• Keywords
• Help

39. Variables

40. <type> var_name = val;
int int_ex = 10;
int_ex = 10

41. int_ex = 10
long_ex = 1000000000000L
float_ex = 1.1
string_ex = “Welcome”
boolean_ex = True

42. type()

43. print type(int_ex)
print type(long_ex)
print type(float_ex)
print type(string_ex)
print type(boolean_ex)

44. boolean_one = True
boolean_two = False
print boolean_one and boolean_two
print boolean_one or boolean_two
print not boolean_two

45. int_one = 11
int_two = 5
print int_one / int_two
print float(int_one) / float(int_two)
print float(int_one) / int_two
print int_one / float(int_two)

46. type casting

47. int_ex = 11
float_ex = 8.8
boolean_ex = True
print float (int_ex)
print int (float_ex)
print int (boolean_ex)

48. int_one = 11
int_two = 5
print int_one + int_two
print int_one - int_two
print int_one * int_two
print int_one / int_two
print int_one % int_two
print int_one ** int_two

49. int_one = 11
int_two = 5
print int_one > int_two
print int_one >= int_two
print int_one < int_two
print int_one <= int_two
print int_one == int_two
print int_one != int_two

50. Lets do some Maths

51. import math
(or)
from math import sqrt

52. dir (math)

53. int_one = 11
int_two = 5
import math
print math.sqrt (int_one)
import math
from math import factorial
print math.pi
print factorial (int_two)

54. Lets Talk to the User

55. raw_input()
(or)
raw_input([prompt_string])

56. user_input = raw_input()
print “You have Entered “ , user_input
user_input = raw_input(“Input Please : “)
print type(user_input)

57. int_one = raw_input (“Number 1 : “)
int_two = raw_input (“Number 2 : “)
print int_one + int_two
print int(int_one) + int(int_two)

58. The Nightmare Strings

59. “Hey, What’s up?”

60. ‘ ’
“ ”
“““ ”””
‘‘‘ ’’’

61. print ‘ example text ’
print “ example text ”
print “““ example of long …..
…. text ”””
print ‘‘‘ example of long …..
…. text ’’’

62. print ‘ String with “double” quotes ’
print “String with ‘single’ quote ”
print ““ Hey what‘s up””
print ‘“ Hey what‘s up”’
print “““ “ Hey what‘s up ” ”””
print ‘‘‘ “ Hey what‘s up ” ’’’

63. Don’t Mess with
Quotes

64. Collections

65. 0 1 2 3 4 5
10 10.1 ‘A’ ‘ABC’ 2 True
-6 -5 -4 -3 -2 -1

66. 0 1 2 3 4 5
10 10.1 ‘A’ ‘ABC’ 2 True
-6 -5 -4 -3 -2 -1
list_ex = [ 10, 10.1, ‘A’, ‘ABC’, 2, True ]
tuple_ex = ( 10, 10.1, ‘A’, ‘ABC’, 2, True )

67. List [] vs Tuple ()

68. 0 1 2 3 4 5
10 10.1 ‘A’ ‘ABC’ 2 True
-6 -5 -4 -3 -2 -1
tuple_ex = ( 10, 10.1, ‘A’, ‘ABC’, 2, True )
• tuple_ex[0] • tuple_ex[-6]
• tuple_ex[1] • tuple_ex[-5]
• tuple_ex[2] • tuple_ex[-4]
• tuple_ex[3] • tuple_ex[-3]
• tuple_ex[4] • tuple_ex[-2]
• tuple_ex[5] • tuple_ex[-1]

69. Tuple / List Tricks

70. tuple_ex = (100, )
list_ex = [100, ]
tuple_ex = tuple(‘gobi’)
list_ex = list(‘gobi’)

71. Lets Slice!

72. 0 1 2 3 4 5 6 7 8 9
1 2 3 4 5 6 7 8 9 10
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1
list_ex = [1, 2, 3, 4, 5, 6, 7, 8, 9 , 10, ]
print list_ex[:3]
print list_ex[3:]
print list_ex[:-3]
print list_ex[-3:]

73. 0 1 2 3 4 5 6 7 8 9
1 2 3 4 5 6 7 8 9 10
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1
list_ex = [1, 2, 3, 4, 5, 6, 7, 8, 9 , 10, ]
print list_ex[0:1]
print list_ex[0:2]
print list_ex[-2:-1]
print list_ex[-3:-1]

74. 0 1 2 3 4 5 6 7 8 9
1 2 3 4 5 6 7 8 9 10
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1
list_ex = [1, 2, 3, 4, 5, 6, 7, 8, 9 , 10, ]
print list_ex[0:10:2]
print list_ex[1:10:2]

75. 0 1 2 3 4 5 6 7 8 9
1 2 3 4 5 6 7 8 9 10
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1
list_ex = [1, 2, 3, 4, 5, 6, 7, 8, 9 , 10, ]
print len(list_ex)
print max(list_ex)
print min(list_ex)

76. Lets Join!

77. city = list(‘gobi’)
city[len(city):] = “chettipalayam”
“”.join(city)

78. ipl_teams = [‘CSK’, ‘DD’, ‘KXIP’, ‘KKR’, ‘MI’, ‘PWI’, ‘RR’, ‘RCB’, ‘SRH’,]
“, ”.join(ipl_teams)

79. str_ipl_teams = “, ”.join(ipl_teams)
list_ipl_teams = list(str_ipl_teams )
list_ipl_teams[str_ipl_teams.rfind(", ")] = " and“
print "".join(list_ipl_teams)

80. ipl_teams = [‘CSK’, ‘DD’, ‘KXIP’, ‘KKR’, ‘MI’, ‘PWI’, ‘RR’, ‘RCB’,]
ipl_teams.append(‘SRH’)

81. ipl_teams = [‘CSK’, ‘DD’, ‘KXIP’, ‘KKR’, ‘MI’, ‘PWI’, ‘RR’, ‘RCB’,]
ipl_teams.remove(‘SRH’)
del ipl_teams[-1]

82. ipl_teams = [‘CSK’, ‘DD’, ‘KXIP’, ‘KKR’, ‘MI’, ‘PWI’, ‘RR’, ‘RCB’,]
ipl_teams.insert (1, ‘SRH’)

83. ipl_teams = [‘CSK’, ‘SRH’, ‘DD’, ‘KXIP’, ‘KKR’, ‘MI’, ‘PWI’, ‘RR’, ‘RCB’,]
ipl_teams.sort()

84. The Control Flow

85. Lets begin with a
Search

86. list_ex = [1, 2, 3, 4, 5]
print 3 in list_ex1

87. title_winners = [‘CSK’, ‘RR’, ‘DC’, ‘KKR’]
print ‘CSK’ in title_winners

88. my_city = “Gobichettipalayam”
print ‘chetti’ in my_city

89. while

90. i=1
while i <= 10:
print i,
i=i+1

91. for

92. for i in range(1, 11):
print i,

93. for i in range(11):
if i % 2 == 0:
print i

94. for i in range(11):
if i % 2 == 0:
print “Even : ”, i
else :
print “Odd: ”, i

95. for i in range(11):
if i == 0:
pass
elif i % 2 == 0:
print “Even : ”, i
else :
print “Odd: ”, i

96. for i in range(11):
if i == 0:
continue
elif i % 2 == 0:
print “Even : ”, i
else :
print “Odd: ”, i

97. for i in range(11):
if i == 0:
break
elif i % 2 == 0:
print “Even : ”, i
else :
print “Odd: ”, i

98. title_winners = ['CSK', 'RR', 'DC', 'KKR']
for team in title_winners:
print team,

99. for i in range(11):
print i,
else:
print “No Break executed in for”

100. Null Factor
None

101. list_ex = []
if list_ex:
print “List is not Empty”
else:
print “List is Empty”

102. list_ex = None
if list_ex:
print “List is not None”
else:
print “List is None”

103. Error Handling

104. The OO Python

105. Thank You!
siva@sivaa.in
bit.ly/sivaa_in bit.ly/sivasubramaniam

106. References
http://www.slideshare.net/narendra.sisodiya/python-presentation-presentation
http://www.f-106deltadart.com/photo_gallery/var/albums/NASA-Research/nasa_logo.png?m=1342921398
http://www.seomofo.com/downloads/new-google-logo-knockoff.png
http://www.huntlogo.com/wp-content/uploads/2011/11/US-Navy-Logo.png
http://3.bp.blogspot.com/_7yB-eeGviiI/TUR471pyRpI/AAAAAAAAIBI/X705lo5Gjqc/s1600/Yahoo_Logo24.JPG
http://www.thetwowayweb.com/wp-content/uploads/2012/09/youtube_logo.png