pythonchallenge

Solve Problems in http://www.pythonchallenge.com

32

use wget to download a file provider username and password

1. user:password@domain url
2. --user=${username} --password=${password}

• wget http://kohsamui:thailand@www.pythonchallenge.com/pc/rock/warmup.txt
• wget --user=kohsamui --password=thailand www.pythonchallenge.com/pc/rock/warmup.txt

31

result : http://www.pythonchallenge.com/pc/rock/arecibo.html

• the picture lead to-> http://www.pythonchallenge.com/pc/rock/grandpa.html
• use firefox visit the url get the hint: island:country
• username:kohsamui password:thailand

30

result: http://www.pythonchallenge.com/pc/ring/grandpa.html

import csv

• csv lib for handle csv tables, csv for Comma-Separated Values
• 7367 factored result: 53 and 139

29

result: http://www.pythonchallenge.com/pc/ring/yankeedoodle.html

• do you find these unnecessary empty lines in the source page of guido.html

28

result: http://www.pythonchallenge.com/pc/ring/guido.html

• use image.split() to split RGB channels
• im.bands() return number of im's channels
• ring means "green" if you visit "green.html" will get response "yes"
• whodunnit is an word means "who is the murderer"

27

result: http://www.pythonchallenge.com/pc/ring/bell.html auth=(repeat, switch)

• author use python2 keyword, which has some different with python3
• use assert to do assert
• tobytes() method for Image in PIL: Return image as a bytes object.
• getpalette() method for Image in PIL: Returns the image palette as a list.

26

result: http://www.pythonchallenge.com/pc/hex/speedboat.html

import hashlib

• we get mybroken.zip in level 24
• the decent means leopold mozart
• we have sent an email to leopold mozart in level 19
• fix the broken zip file to match the md5

25

result: http://www.pythonchallenge.com/pc/hex/decent.html

• lake1.html means there is a file named with lake2
• imagine how they sound

24

result: http://www.pythonchallenge.com/pc/hex/lake.html

import logging

• logging helps me to do analyze

import constant

• I put big size array in my custom constant.py, and i can import it
• the author uses "latin1" Charset

23

result: http://www.pythonchallenge.com/pc/hex/ambiguity.html

import this

• rot13
• this is an undocumented module.

22

result: http://www.pythonchallenge.com/pc/hex/bonus.html

from PIL import Image
from PIL import ImageSequence
import turtle, time

• use ImageSequence to get the frame number of a gif

a = 10
b = 3
print(a / b) # 3.3333333333333335
print(a // b) # 2
print(a % b) # 1 

21

result: http://www.pythonchallenge.com/pc/hex/copper.html

import zlib
import bz2

• Here is a List of file signatures

20

result: password is redavni

import requests
import zipfile

• requests is a good lib for http request
• request an url with username and password
• breakpoint resume
• you shoule know a http header {"RANGE":"bytes 0-500"}
• revers
• ZIP file Magic number: none or "PK\x03\x04" or "PK\x05\x06"(empty) or "PK\x07\x08"(spanned), PK for Phil Katz
• find points in 2123456789 points

19

result: http://www.pythonchallenge.com/pc/hex/idiot2.html

import base64
import wave

• use base64 to decode these codes
• use wave to read and write frame
• the sea is yellow the land is blue，which is out of order
• if you email to leopold with “sorry” as subject, you will get a surprise

18

result: http://www.pythonchallenge.com/pc/hex/bin.html username:butter password:fly

import difflib

• the obvious different between two picture is brightness.

gunzip deltas.gz

• png file start with: 0x89 0x50 0x4E 0x47 0x0D 0x0A 0x1A 0x0A
• 0x89 is png's magic number,all jpg file start with 0xFF
• 0x50 decode in utf-8 is P, 0x4E for N, 0x47 for G
• use three tag "+", "-", " " to describe the difference between two files

when you say a php file, there are some function in it

• Loop: http://www.pythonchallenge.com/pc/def/linkedlist.php
• RPC: http://www.pythonchallenge.com/pc/phonebook.php

17

result: http://www.pythonchallenge.com/pc/return/balloons.html

from http.cookiejar import CookieJar
import urllib.parse
import bz2
import requests

• the small pic in left bottom director us to Level 3
• use CookieJar to catch cookies
• use bz2 to decompress

is it the 26th already? call his father and inform him that "the flowers are on their way". he'll understand.

• 26th director us to Level 15
• mozart‘s farther is Leopold Mozart
• call director us to phonebook in Level 12
• Level 12 Bert tell us to use the first name
• inform him let us remember that the cookies are {"info":"value"}

16

result: http://www.pythonchallenge.com/pc/return/romance.html

from PIL import Image

• this gif is a P mode picture which use one 8 bit number to declare a color
• straight is a way to handle these pixels

15

result: http://www.pythonchallenge.com/pc/return/mozart.html

from calendar import isleap
from datetime import date

• year 1756 is a leap year
• 1756-1-27 is Tursday
• mozart's birthday is 1756-1-27
• mozart is the second youngest boy in his family

14

result: http://www.pythonchallenge.com/pc/return/uzi.html

from PIL import Image
from PIL import ImageDraw

• the key of this problem is to use 100 * 100 = 100 + 99 + 99 + 98 + 98 + 97 + 97 + ...
• the size of cat.png is 100 * 100
• use ImageDraw.point()
• result is "wire/cat.png"

while(
    left(0,0) -> right(99,0)  100
    up(99,1) -> down(99,99)   99
    right(99,98) -> left(99,0) 99
    down(98,0) -> up (1,0) 98
)

13

result: http://www.pythonchallenge.com/pc/return/italy.html

import xmlrpc.client

It's amazing that RPC tech has so much long history.

system.listMethods
This method returns a list of the methods the server has, by name.

POST below with application/xml to server.

<?xml version="1.0"?>
<methodCall>
   <methodName>phone</methodName>
   <params>
      <param>
         <value><string>Bert</string></value>
         </param>
      </params>
   </methodCall>

Question 12 evil4.jpg tell us the evil is Bert(IE can open evil4.jpg or change the suffix to .txt).

12

result: http://www.pythonchallenge.com/pc/return/disproportional.html

use python IO to divide the gfx into 5(5 is the count of playing card in the pic) jpg files.

11

result: http://www.pythonchallenge.com/pc/return/evil.html

from PIL import Image
from PIL import ImageDraw

the hint is in the html'title: odd, even

10

result: http://www.pythonchallenge.com/pc/return/5808.html

with pycharm IDE, I can debug the code easier.

the method of find rule of a is:look at a[i - 1], do count
1
the next is one 1: 11
the next is two 1: 21
the next is one 2 one 1: 1211
the next is one 1 one 2 two 2: 111221
the next is three 1 two 2 one 1: 312211

9

result:http://www.pythonchallenge.com/pc/return/bull.html

the html knowledge learn from 8 help me.

8

result: http://www.pythonchallenge.com/pc/return/good.html

un:huge pw:file

html knowledge: img-usemap="#--", map, area, sharp, poly, coords.

import bz2

7

result: http://www.pythonchallenge.com/pc/def/integrity.html

from PIL import Image

use PIL module to find the block's pixel with getpixel(), then use chr() to translate the code

6

result: http://www.pythonchallenge.com/pc/def/oxygen.html

import zipfile

zip file not only can bi unzip, can contains a lot of comments.

every level will play with a new lib.

5

result: http://www.pythonchallenge.com/pc/def/channel.html

import pickle

every line elements add up to 96

4

result: http://www.pythonchallenge.com/pc/def/peak.html

import requests

this is a http client lib with to do http request.

3

result: http://www.pythonchallenge.com/pc/def/linkedlist.html

transfer to: http://www.pythonchallenge.com/pc/def/linkedlist.php

2

result: http://www.pythonchallenge.com/pc/def/equality.html

1

result: http://www.pythonchallenge.com/pc/def/ocr.html

• ord()
• chr()
• isalpha()
• isalnum()

True: 'a'.isalpha() True: 'a'.isalnum()

False: '.'.isalpha() False: '.'.isalnum()

True: '1'.isalnum() False: '1'.isalpha()

0

pow(2,3)

start: http://www.pythonchallenge.com/pc/def/0.html

result: http://www.pythonchallenge.com/pc/def/map.html