PythonChallenge
To read the pre-Level of PythonChallenge at this site: Ethan.Penx Blog in ITeye
Table of Contents
Level 7
Riddle Page L7: http://www.pythonchallenge.com/pc/def/oxygen.html
The title of the page is “smarty”, and there’s a picture with a strip of greyscale squares across the middle which is at the top of the page. At the sight of the clue “smarty”, what occurs to me is a Python Module named Smartypants, but sadly, there’s nothing I can get by smartypants.
Mabye the clue is in those greyscale squares, with the greyscale level (range from 0-255) encoding something in it, whatever, try it first.
Downloaded the picture(named it ‘oxygen.png’).
>>> import Image
>>> im = Image.open("/Users/xing/Desktop/oxygen.png")
>>> width, height = im.size
>>> im.getpixel((0, h//2))
(115, 115, 115, 255)
>>> print chr(115), chr(255)
s ?
Well, that make sense. Let’s guess that each block is 4 pixel wider:
>>> smarty = [chr(im.getpixel((i, h//2))[0]) for i in range(0, width, 4)]
>>> ''.join(smarty)
'ssmaarrtt gguuyy, yyoou mmaadee iit.. tthee nnexxtt leevveel iiss [[11005,, 11100,, 11166,, 110011, 11003,, 11144,, 10055,, 111166, 11221]]rbecbc'
>>>
Obviously, I choose the wrong pixel width, try it a few of times.
Turns out, the colour changes every 7 pixels.
>>> print ''.join([chr(im.getpixel((i, h//2))[0]) for i in range(0, width, 7)])
smart guy, you made it. the next level is [105, 110, 116, 101, 103, 114, 105, 116, 121]pe_
>>> print ''.join(map(chr, [105, 110, 116, 101, 103, 114, 105, 116, 121]))
integrity
>>>
So, change the url (oxygen –> integrity) to getting Level 8: Riddle Page L8: http://www.pythonchallenge.com/pc/def/integrity.html
The Related
There’s something to help understand all the Image stuff as following:
functions:
-
Image.getpixel(xy):
> Returns the pixel value at a given position.
Parameters: xy – The coordinate, given as (x, y).
Returns: The pixel value. If the image is a multi-layer image, this method returns a tuple. -
map(function, sequence[, sequence, …]) -> list
> Return a list of the results of applying the function to the items of the argument sequence(s). If more than one sequence is given, the function is called with an argument list consisting of the corresponding item of each sequence, substituting None for missing values when not all sequences have the same length. If the function is None, return a list of the items of the sequence (or a list of tuples if more than one sequence).
Level 8
Riddle Page L8: http://www.pythonchallenge.com/pc/def/integrity.html
Well, there’s a picture with a bee flying up the flower, and the clues “Where is the missing link?” at the bottom of the page, clicked the picture takes us to a password-protected page for area “inflate”. And the title of this page is “working hard?”. Seriously? working hard? I’m totally confused…
Let’s do it the old ways, check the source code of this page, it’s showed me a series of messy strings, Unfortunately, I can’t figure out what types of coding it used, neither encoding it.
Fine, google the messy strings, turns out, it’s brz2 compressed file format.
>>> un = "BZh91AY&SYA\xaf\x82\r\x00\x00\x01\x01\x80\x02\xc0\x02\x00 \x00!\x9ah3M\x07<]\xc9\x14\xe1BA\x06\xbe\x084"
>>> pw = 'BZh91AY&SY\x94$|\x0e\x00\x00\x00\x81\x00\x03$ \x00!\x9ah3M\x13<]\xc9\x14\xe1BBP\x91\xf08'
>>> import bz2
>>> bz2.decompress(un)
'huge'
>>> bz2.decompress(pw)
'file'
So, entered the username&password come to the Level 9: http://www.pythonchallenge.com/pc/return/good.html
BTW, here’s the hint comes from official solutions:
You see a bee in the picture. She sounds busy too. What could that mean? bee? busy. busy? busy too ? bz2? The hint in the password box says “inflate” so you consider to try to decompress the strings.
THe Related
functions:
-
bz2.compress(data[, compresslevel])
Compress data in one shot. If you want to compress data sequentially, use an instance of BZ2Compressor instead. The compresslevel parameter, if given, must be a number between 1 and 9; the default is 9. -
bz2.decompress(data)
Decompress data in one shot. If you want to decompress data sequentially, use an instance of BZ2Decompressor instead.
Level 9
Riddle Page Level 9: (Uname: huge, Pwd: file) http://www.pythonchallenge.com/pc/return/good.html
The title of this page is “connect the dots”, and there are a long lists of numbers for “first”&”second” in the source page. Maybe the numbers are the coordinates of dots which join another picture? Just do it.
MBP-Ethan:TextWrangler xing$ vim pythonchallenge9.py
'''
copy & paste the "first" and "second"
'''
MBP-Ethan:TextWrangler xing$ python pythonchallenge9.py
# enter python shell
>>> from pythonchallenge9 import *
>>> len(list1), min(list1), max(list1)
(442, 77, 403)
>>> len(list2), min(list2), max(list2)
(112, 77, 220)
>>> import Image
>>> help(Image.new)
new(mode, size, color=0)
Create a new image
>>> im = Image.new('1', (600, 600), "white")
>>> import ImageDraw
>>> line1 = zip(list1[0::2], list1[1::2])
>>> line2 = zip(list2[0::2], list2[1::2])
>>> draw = ImageDraw.Draw(im)
>>> draw.line(line1)
>>> draw.line(line2)
>>> im.show()
A bull showed on the screen.
Well, same old, changing the url to get to Level10: http://www.pythonchallenge.com/pc/return/bull.html
The Related
functions
-
Image.new(mode, size, color) ⇒ image
Creates a new image with the given mode and size. Size is given as a (width, height)-tuple, in pixels. The color is given as a single value for single-band images, and a tuple for multi-band images (with one value for each band). In 1.1.4 and later, you can also use color names (see the ImageColor module documentation for details) If the color argument is omitted, the image is filled with zero (this usually corresponds to black). If the color is None, the image is not initialised. This can be useful if you’re going to paste or draw things in the image.from PIL import Image im = Image.new("RGB", (512, 512), "white") -
Draw a Grey Cross Over an Image
import Image, ImageDraw im = Image.open("lena.pgm") draw = ImageDraw.Draw(im) draw.line((0, 0) + im.size, fill=128) draw.line((0, im.size[1], im.size[0], 0), fill=128) del draw # write to stdout im.save(sys.stdout, "PNG")
Level 10
Riddle page Level 10: http://www.pythonchallenge.com/pc/return/bull.html
There’s a picture of a bull and the clue is “len(a[30]) = ?”. Display the source page, and clicking the href=”sequence.txt” get to the another page which is reveals “a = [1, 11, 21, 1211, 111221, “. Obviously, we’re asked to solve the sequence puzzle.
Type the numbers into the Online Encyclopedia of Integer Sequences, (OEIS). Turns out, this one is A005150, “Look and say sequence.”
There’s Python code in the OEIS for computing the values of the sequence, but it’s simpler to follow the cross-reference for the length of the n-th term to find the sequence A005341, it gives the length of the 31st term as 5808.
So, here’s the url of Level 11: http://www.pythonchallenge.com/pc/return/5808.html