Python Challenge - Level 5
Problem
pronounce it
Page Source:
<peakhell src="banner.p" />
<!-- peak hell sounds familiar ? -->
peakhell, peakhell... sounds like... "pickle"(which is Python's object serialization module)
Solution
Let's print out the raw data:
>>> from urllib.request import urlopen
>>> raw = urlopen("http://www.pythonchallenge.com/pc/def/banner.p").read()
>>> raw
b"(lp0\n(lp1\n(S' '\np2\nI95\ntp3\naa..."
Normally plain text can be encoded as utf-8 or some other form, once we call .decode() it will reveal it self,
however this one is tough:
>>> raw.decode()
"(lp0\n(lp1\n(S' '\np2\nI95\ntp3\naa..."
As hinted, let's use pickle to deserialize it:
>>> import pickle
>>> data = pickle.load(urlopen("http://www.pythonchallenge.com/pc/def/banner.p"))
>>> data
[[(' ', 95)], [(' ', 14), ('#', 5), (' ', 70), ('#', 5), (' ', 1)], [(' ', 15), ('#', 4), (' ', 71), ('#', 4), (' ', 1)], [(' ', 15), ('#', 4), (' ', 71), ('#', 4), (' ', 1)], [(' ', 15), ('#', 4), (' ', 71), ('#', 4), (' ', 1)], [(' ', 15), ('#', 4), (' ', 71), ('#', 4), (' ', 1)], [(' ', 15), ('#', 4), (' ', 71), ('#', 4), (' ', 1)], [(' ', 15), ('#', 4), (' ', 71), ('#', 4), (' ', 1)], [(' ', 15), ('#', 4), (' ', 71), ('#', 4), (' ', 1)], [(' ', 6), ('#', 3), (' ', 6), ('#', 4), (' ', 3), ('#', 3), (' ', 9), ('#', 3), (' ', 7), ('#', 5), (' ', 3), ('#', 3), (' ', 4), ('#', 5), (' ', 3), ('#', 3), (' ', 10), ('#', 3), (' ', 7), ('#', 4), (' ', 1)], [(' ', 3), ('#', 3), (' ', 3), ('#', 2), (' ', 4), ('#', 4), (' ', 1), ('#', 7), (' ', 5), ('#', 2), (' ', 2), ('#', 3), (' ', 6), ('#', 4), (' ', 1), ('#', 7), (' ', 3), ('#', 4), (' ', 1), ('#', 7), (' ', 5), ('#', 3), (' ', 2), ('#', 3), (' ', 5), ('#', 4), (' ', 1)], [(' ', 2), ('#', 3), (' ', 5), ('#', 3), (' ', 2), ('#', 5), (' ', 4), ('#', 4), (' ', 3), ('#', 3), (' ', 3), ('#', 4), (' ', 4), ('#', 5), (' ', 4), ('#', 4), (' ', 2), ('#', 5), (' ', 4), ('#', 4), (' ', 3), ('#', 3), (' ', 5), ('#', 3), (' ', 3), ('#', 4), (' ', 1)], [(' ', 1), ('#', 3), (' ', 11), ('#', 4), (' ', 5), ('#', 4), (' ', 3), ('#', 3), (' ', 4), ('#', 3), (' ', 4), ('#', 4), (' ', 5), ('#', 4), (' ', 2), ('#', 4), (' ', 5), ('#', 4), (' ', 2), ('#', 3), (' ', 6), ('#', 4), (' ', 2), ('#', 4), (' ', 1)], [(' ', 1), ('#', 3), (' ', 11), ('#', 4), (' ', 5), ('#', 4), (' ', 10), ('#', 3), (' ', 4), ('#', 4), (' ', 5), ('#', 4), (' ', 2), ('#', 4), (' ', 5), ('#', 4), (' ', 2), ('#', 3), (' ', 7), ('#', 3), (' ', 2), ('#', 4), (' ', 1)], [('#', 4), (' ', 11), ('#', 4), (' ', 5), ('#', 4), (' ', 5), ('#', 2), (' ', 3), ('#', 3), (' ', 4), ('#', 4), (' ', 5), ('#', 4), (' ', 2), ('#', 4), (' ', 5), ('#', 4), (' ', 1), ('#', 4), (' ', 7), ('#', 3), (' ', 2), ('#', 4), (' ', 1)], [('#', 4), (' ', 11), ('#', 4), (' ', 5), ('#', 4), (' ', 3), ('#', 10), (' ', 4), ('#', 4), (' ', 5), ('#', 4), (' ', 2), ('#', 4), (' ', 5), ('#', 4), (' ', 1), ('#', 14), (' ', 2), ('#', 4), (' ', 1)], [('#', 4), (' ', 11), ('#', 4), (' ', 5), ('#', 4), (' ', 2), ('#', 3), (' ', 4), ('#', 4), (' ', 4), ('#', 4), (' ', 5), ('#', 4), (' ', 2), ('#', 4), (' ', 5), ('#', 4), (' ', 1), ('#', 4), (' ', 12), ('#', 4), (' ', 1)], [('#', 4), (' ', 11), ('#', 4), (' ', 5), ('#', 4), (' ', 1), ('#', 4), (' ', 5), ('#', 3), (' ', 4), ('#', 4), (' ', 5), ('#', 4), (' ', 2), ('#', 4), (' ', 5), ('#', 4), (' ', 1), ('#', 4), (' ', 12), ('#', 4), (' ', 1)], [(' ', 1), ('#', 3), (' ', 11), ('#', 4), (' ', 5), ('#', 4), (' ', 1), ('#', 4), (' ', 5), ('#', 3), (' ', 4), ('#', 4), (' ', 5), ('#', 4), (' ', 2), ('#', 4), (' ', 5), ('#', 4), (' ', 2), ('#', 3), (' ', 12), ('#', 4), (' ', 1)], [(' ', 2), ('#', 3), (' ', 6), ('#', 2), (' ', 2), ('#', 4), (' ', 5), ('#', 4), (' ', 2), ('#', 3), (' ', 4), ('#', 4), (' ', 4), ('#', 4), (' ', 5), ('#', 4), (' ', 2), ('#', 4), (' ', 5), ('#', 4), (' ', 3), ('#', 3), (' ', 6), ('#', 2), (' ', 3), ('#', 4), (' ', 1)], [(' ', 3), ('#', 3), (' ', 4), ('#', 2), (' ', 3), ('#', 4), (' ', 5), ('#', 4), (' ', 3), ('#', 11), (' ', 3), ('#', 4), (' ', 5), ('#', 4), (' ', 2), ('#', 4), (' ', 5), ('#', 4), (' ', 4), ('#', 3), (' ', 4), ('#', 2), (' ', 4), ('#', 4), (' ', 1)], [(' ', 6), ('#', 3), (' ', 5), ('#', 6), (' ', 4), ('#', 5), (' ', 4), ('#', 2), (' ', 4), ('#', 4), (' ', 1), ('#', 6), (' ', 4), ('#', 11), (' ', 4), ('#', 5), (' ', 6), ('#', 3), (' ', 6), ('#', 6)], [(' ', 95)]]
OK! So data is a list of lists of tuples... It does not look like a banner(the file name), but more like the result of a simple string compression: convert the repetitive characters to tuples of (character, number of appearance). This level is all about serialization and compression, isn't it. Let's unravel the string:
>>> for line in data:
... print("".join([k * v for k, v in line]))
...
##### #####
#### ####
#### ####
#### ####
#### ####
#### ####
#### ####
#### ####
### #### ### ### ##### ### ##### ### ### ####
### ## #### ####### ## ### #### ####### #### ####### ### ### ####
### ### ##### #### ### #### ##### #### ##### #### ### ### ####
### #### #### ### ### #### #### #### #### ### #### ####
### #### #### ### #### #### #### #### ### ### ####
#### #### #### ## ### #### #### #### #### #### ### ####
#### #### #### ########## #### #### #### #### ############## ####
#### #### #### ### #### #### #### #### #### #### ####
#### #### #### #### ### #### #### #### #### #### ####
### #### #### #### ### #### #### #### #### ### ####
### ## #### #### ### #### #### #### #### #### ### ## ####
### ## #### #### ########### #### #### #### #### ### ## ####
### ###### ##### ## #### ###### ########### ##### ### ######
You got it:
channel
Put Everything Together
from urllib.request import urlopen
import pickle
h = urlopen("http://www.pythonchallenge.com/pc/def/banner.p")
data = pickle.load(h)
for line in data:
print("".join([k * v for k, v in line]))