Happy strings

Yup, it's Dada again! I love useless things!

So, I was browsing through Think Python and found an exercise to print stuff on the screen. I figured it would be fun just to make it in one go - no loops or anything.

Here's how it looked. And by the way, you can run all the code in a Python interpreter - it's all safe.

 
1 print \ 
2 ( ('+' + 5 * '-') * 3 + '+' + "\n" + \ 
3 ( ( '|' + 5 * ' ' ) * 3 + '|' + "\n" ) * 2 ) * 3 + \ 
4 ('+' + 5 * '-') * 3 + '+' 

But then I figured... that's not nearly fun enough. So, long story short, I made this:

 
1 print \ 
2 ',' + '_' * 2 + ',' + '\n' + \ 
3 '(' + 'x' * 2 + ')' + '_' * 4 + '\n' + \ 
4 '(' + '_' * 2 + ')' + ' ' * 4 + ')' + '\\' + '\n' \ 
5 + ' ' + 'U' + '|' * 2 + '-' * 2 + '|' * 2 + ' ' * 2 + '*' 

Much more fun.

So then, I took it up a notch and wrote a program to generate that sort of thing. It took me three complete attempts, because I mostly produced bugs today... damn bugs. But it's all nice and thought-through now.

Here's the code:

 
 1 #!/usr/bin/python 
 2 # 
 3 # Happy strings 
 4 #  
 5 # More or less purposeless script, which takes strings, splits 
 6 # them up  into characters and then creates a Python print  
 7 # statements which  reproduce the same strings in a  
 8 # complicated, slightly less readable form... but a slightly  
 9 # happier form, methinks. 
10 # 
11 # Parameters: 
12 #   a list of strings to reproduce 
13 # Author: 
14 #   Konrad Siek 
15  
16 import sys
17  
18 def escape_string(string):
19     if string in ["\'", "\"", "\\"]:
20         return "\\" + string
21     elif string == "\n":
22         return "\\n" 
23     return string
24  
25 def output_string(string, counter, last):
26     output = "'" + escape_string(string) + "'" 
27     if counter != 1:
28         output += ' * ' + str(counter)
29     if not last:
30         output += ' + ' 
31     return output
32  
33 for string in sys.argv[1:]:
34     output = 'print ' 
35     previous = None 
36     counter = 0 
37     length = len(string)
38     for i in range(0, length):
39         character = string[i]
40         if character == previous:
41             counter += 1 
42         else:
43             if previous != None:
44                 output += output_string(
45                     previous,
46                     counter,
47                     False 
48                 )
49             counter = 1 
50             previous = character
51     output += output_string(
52         previous,
53         counter,
54         True 
55     )
56     print output

Yay!

The code is also available at GitHub as python/happy_strings.py.