Convert text to ASCII and ASCII to text

Python has a very simple way to convert text to ASCII and ASCII to text.

To find the ASCII value of a character use the ord() function.
Example:
>>> ord('B')
66

To get a character from it's ASCII value use the chr() function.
Example:
>>> chr(65)
'A'

Here is a program to get the list of all characters along with their values:


# program to print the list of characters and their ASCII values
for value in range(0, 255):
   print "ASCII Value:", value, "\t", "Character:", chr(value), "\n"

Here is another simple ASCII encoding-decoding program:


# Convertion from text to ASCII codes

message = raw_input("Enter message to encode: ")

print "Decoded string (in ASCII):"
for ch in message:
   print ord(ch),
print "\n\n"

# Convertion from ASCII codes to text

message = raw_input("Enter ASCII codes: ")

decodedMessage = ""

for item in message.split():
   decodedMessage += chr(int(item))   

print "Decoded message:", decodedMessage

Hope you got a clear understanding of how to convert between text and ASCII code.

Comments

aatiis said…

Nice...
I used to use chr() and ord() to store huge numbers (like 512bit integers) by bit-shifting by 8 and &ing. Actually I used '%c' % 65, but I think it's pretty much the same as chr(65).

May 16, 2008 at 7:24 AM

Steve Kehlet said…

Thanks, very helpful.

June 11, 2009 at 3:06 AM

Jabba Laci said…

If you use range(0,255), then you'll miss the value 255. I suggest range(256). Another solution for producing the ASCII table:

for char in range(256):
print "%d: %c" % (char, char)

I started to learn Python a week ago. I'm glad that I found your blog, it'll be useful for me.

October 11, 2009 at 12:00 PM

Attila Oláh said…

Yup, string formatting using "%c" is an elegant solution. And you're right about the 256 too, since 256 = len(range(256)), of course :)

October 11, 2009 at 7:33 PM

Naveen said…

Nice post. Pretty much clarifies about the ASCII chars (0-255). How about UTF-8 charset ? For a given character (for example ò), how to find its Unicode representation ?

January 10, 2010 at 1:30 AM

What do you mean by "unicode representation"? u'ó' *is* the Unicode representation. You can encode/decode, of course. I.e.

>>> [ord(c) for c in u'ó'.encode('utf-8')]
[194, 179]

On the other hand:
>>> '%c%c' % (194, 179)
'\xc2\xb3'
>>> 'ó'
'\xc3\xb3'

Can you tell me, why '%c%c' % (194, 179) != 'ó'? And why:

>>> print '%c%c' % (195, 179)
'ó'

Bests,
Attila

January 10, 2010 at 3:25 AM

'%c%c' % (194, 179) != 'ó'
May be because %c %c took the default code page of the underlying stream which is why we did not get ó.

I just took a wild-guess.. Correct me if I am wrong.

January 10, 2010 at 2:14 PM

The :mod:`unicodedata` module might be helpful in this case: this is retrieved from http://www.python.org/doc/2.6.4/library/unicodedata.html :

>>> import unicodedata
>>> unicodedata.lookup('LEFT CURLY BRACKET')
u'{'
>>> unicodedata.name(u'/')
'SOLIDUS'
>>> unicodedata.decimal(u'9')
9
>>> unicodedata.decimal(u'a')
Traceback (most recent call last):
File "", line 1, in ?
ValueError: not a decimal
>>> unicodedata.category(u'A') # 'L'etter, 'u'ppercase
'Lu'
>>> unicodedata.bidirectional(u'\u0660') # 'A'rabic, 'N'umber
'AN'

January 10, 2010 at 4:53 PM