21

Author: JavaProgrammerLB

21.py

@@ -0,0 +1,29 @@
+import zlib
+import bz2
+
+
+def main():
+    first_step()
+
+
+def first_step():
+    file = open("game/package.pack", "rb")
+    bs = file.read()
+    result = ""
+    while True:
+        if bs.startswith(b"x\x9c"):
+            bs = zlib.decompress(bs)
+            result += " "
+        elif bs.startswith(b"BZ"):
+            bs = bz2.decompress(bs)
+            result += "#"
+        elif bs.endswith(b"\x9cx"):
+            bs = bs[::-1]
+            result += "\n"
+        else:
+            break
+    print(result)
+
+
+if __name__ == "__main__":
+    main()

README.md

@@ -1,6 +1,15 @@
 # pythonchallenge
 Solve Problems in http://www.pythonchallenge.com
 
+#### 21
+result: http://www.pythonchallenge.com/pc/hex/copper.html
+```python
+import zlib
+import bz2
+```
+- Here is a [List of file signatures](https://en.wikipedia.org/wiki/List_of_file_signatures)
+
+
 #### 20
 result: password is redavni
 ```python
@@ -23,9 +32,9 @@ import base64
 import wave
 ```
 - use base64 to decode these codes
-- use wave to reand and write frame
+- 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”, you will find a surprise
+- if you email to leopold with “sorry” as subject, you will get a surprise
 
 
 #### 18