24 {{{ Show the slide containing title }}} |
24 {{{ Show the slide containing title }}} |
25 |
25 |
26 {{{ Show the slide containing the outline slide }}} |
26 {{{ Show the slide containing the outline slide }}} |
27 |
27 |
28 Input and Output are used in almost every program we use. |
28 Input and Output are used in almost every program we use. |
29 In this tutorial, we shall learn |
29 In this tutorial, we shall learn how to |
30 |
30 |
31 * Outputting data |
31 * Output data |
32 * Taking input from the user |
32 * Take input from the user |
33 |
33 |
34 type |
34 type |
35 :: |
35 :: |
36 |
36 |
37 a = "This is a string" |
37 a = "This is a string" |
38 a |
38 a |
39 print a |
39 print a |
40 |
40 |
41 print a prints the value of a which is obvious. |
41 ``print a``, obviously, is printing the value of ``a``. |
42 As you can see, even when you type just a, the value of a is shown. |
42 As you can see, even when you type just a, the value of a is shown. |
43 But there is a difference. |
43 But there is a difference. |
44 |
44 |
45 Typing a shows the value of a while print a prints the string. This difference |
45 Typing a shows the value of a while print a prints the string. This difference |
46 becomes more evident when we use strings with newlines in them. |
46 becomes more evident when we use strings with newlines in them. |
55 While typing print b prints the string and hence the newline. |
55 While typing print b prints the string and hence the newline. |
56 |
56 |
57 Moreover when we type just a, the value a is shown only in interactive mode and |
57 Moreover when we type just a, the value a is shown only in interactive mode and |
58 does not have any effect on the program while running it as a script. |
58 does not have any effect on the program while running it as a script. |
59 |
59 |
|
60 .. #[punch: I think we could show that?] |
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61 |
60 We shall look at different ways of outputting the data. |
62 We shall look at different ways of outputting the data. |
61 |
63 |
62 print statement also accepts the syntax of C's printf statement. |
64 ``print`` statement also accepts the syntax of C's ``printf`` statement. |
63 Various arguments can be passed to print using modifiers. |
65 Various arguments can be passed to ``print`` using modifiers. |
64 type |
66 type |
65 :: |
67 :: |
66 |
68 |
67 x = 1.5 |
69 x = 1.5 |
68 y = 2 |
70 y = 2 |
69 z = "zed" |
71 z = "zed" |
70 print "x is %2.1f y is %d z is %s"%(x,y) |
72 print "x is %2.1f y is %d z is %s"%(x,y) |
71 |
73 |
72 As you can see, the values of x and y are substituted in place of %2.1f and %d |
74 As you can see, the values of x and y are substituted in place of |
|
75 ``%2.1f`` and ``%d`` |
73 |
76 |
74 {{{ Pause here and try out the following exercises }}} |
77 {{{ Pause here and try out the following exercises }}} |
75 |
78 |
76 %% 1 %% What happens when you do ``print "x is %d y is %f" %(x, y)`` |
79 %% 1 %% What happens when you do ``print "x is %d y is %f" %(x, y)`` |
77 |
80 |
78 {{{ continue from paused state }}} |
81 {{{ continue from paused state }}} |
79 |
82 |
80 We see that the int value of x and float value of y are printed corresponding |
83 We see that the ``int`` value of x and ``float`` value of y are |
81 to the modifiers used in the print statement. |
84 printed corresponding to the modifiers used in the print statement. |
82 |
85 |
83 We can also see that print statement prints a new line character at the end of |
86 We can also see that ``print`` statement prints a new line character |
84 line, everytime it is called. This can be suppressed by using a "," at the end |
87 at the end of the line, everytime it is called. This can be suppressed |
85 print statement. |
88 by using a "," at the end ``print`` statement. |
86 |
89 |
87 Let us see this by typing out following code on an editor as print_example.py |
90 Let us see this by typing out following code on an editor as print_example.py |
88 |
91 |
89 {{{ open an editor }}} |
92 {{{ open an editor }}} |
90 type |
93 type |