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Strings Wie ein Informatiker denken lernen String in Zahl wandeln
http://www.hetland.org/python/instant-hacking.php
http://www.faqts.com/knowledge_base/view.phtml/aid/8839/fid/480
[/var/www/opfer_vu/index.html An Introduction to Python ]
http://www.cetus-links.org/oo_python.html
http://www.heise.de/ix/artikel/1999/11/184/
http://www.heise.de/ix/artikel/1996/03/144/
http://www.heise.de/ix/artikel/1999/11/184/02.shtml
http://www.networkcomputing.com/unixworld/tutorial/005/005.html
How to convert hex string to ascii string?
http://www.faqts.com/knowledge_base/view.phtml/aid/8839/fid/480
May 15th, 2001 07:25
Grant Glouser, Alwyn Schoeman
Sometimes you want to convert a string like "777777" to "www". One example of this is when you get binary data on a socket and use binascii.b2a_hex() to get a hex string.
If anyone knows of a better way to go directly from the binary to the ascii, please comment.
The code:
def hextranslate(s):
- res = "" for i in range(len(s)/2):
- realIdx = i*2
res = res + chr(int(s[realIdx:realIdx+2],16))
- realIdx = i*2
if you then do: print hextranslate("777777") You would get: www
One easier approach would be to use binascii.a2b_hex(), which does exactly the same thing as your hextranslate. But it's already written in the binascii module! >>> binascii.a2b_hex('777777') 'www'
The documentation of the binascii module suggests that this will be faster than doing it yourself (with a function like hextranslate), possibly because it is implemented in C. I haven't done any timing tests, so I can't confirm this.
Another thing you may notice in the documentation is that a2b_hex is the inverse of b2a_hex. In other words, a2b_hex(b2a_hex(s)) == s. >>> s = 'www' >>> s2 = b2a_hex(s) >>> s2 '777777' >>> s3 = a2b_hex(s2) >>> s3 'www'
Think about this! If you get "binary" data from a socket, convert it to a hex representation with b2a_hex, then convert it back with a2b_hex or hextranslate, you get exactly the same data you started with. The "binary data" you get from a socket is just a Python string, after all, and it's probably exactly what you needed. No need to convert at all!
http://www.faqts.com/knowledge_base/index.phtml/fid/241 http://www.faqts.com/knowledge_base/index.phtml/fid/199
The same way you write a normal string that ends in a backslash; double it up, eg. """abc\\""".
Don't be fooled by
>>> """asd\\""" 'asd\\'
in the interpreter; if you want to see the string properly, you should do:
>>> print """asd\\""" asd\
r'this ends with a ' '\\'
Python/QuickRef (last modified 2008-11-04 06:59:56)
