Unicode
in python
We Cover these now
● Unicode history
● terms clarity (code point,BOM,utf-8,utf-16)
● decoding and encoding in python
● how...
How it came?
Americans came up with (7 bit)ASCII
representation with english only alphabets as a
standard to exchange info...
What causes unicode born?
To exchange information in all languages, we
got some requirements
● Unique and simple rule was ...
Unicode
Unicode = UCS(universal character set) + bit
representation logic
UCS:
character + code point
(‘a’, 97)
bit repres...
utf-8 is famous, because
● multi-byte encoding
● variable width encoding
● upto 4 byte code points are allowed by utf-8
● ...
decoding
Character to Numeric value(code point)
conversion
● from <type 'str'> to <type 'unicode'>
● it throws maximum “Un...
encoding
● Numeric value(code point) to Characters
● from <type 'unicode'> to <type 'str'>
● it throws maximum “UnicodeEnc...
Rules to Remember…
● Decode early, Unicode everywhere, Encode late
● UTF-8 is the best guess for an encoding
● chardet.det...
How django handles?
>>> def to_unicode(
... obj, encoding='utf-8'):
... if isinstance(obj, basestring):
... if not isinsta...
How to set your python default
encoding standard?
import sys
>>>reload(sys)
>>>sys.setdefaultencoding(‘utf-8’)
>>>sys.getd...
Related python modules..
● chardet.detect()
● unicodedata
● codecs
Thanks for your time
Post your questions.
samples demo….
screenshot2
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Unicode basics in python

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Unicode basics in python

  1. 1. Unicode in python
  2. 2. We Cover these now ● Unicode history ● terms clarity (code point,BOM,utf-8,utf-16) ● decoding and encoding in python ● how django handles these? ● helpful python modules to tackle it Note: BOM is used in utf-16.since, it has multi bytes character code point
  3. 3. How it came? Americans came up with (7 bit)ASCII representation with english only alphabets as a standard to exchange information.(‘A’ - 65, ’a’ - 97) Rest of the world came up with their unaccented english characters ('ä', )in their own way.(messed up)
  4. 4. What causes unicode born? To exchange information in all languages, we got some requirements ● Unique and simple rule was needed ● Adoptable across all machines(windows,ibm, etc..) ● Efficient storage as much possible
  5. 5. Unicode Unicode = UCS(universal character set) + bit representation logic UCS: character + code point (‘a’, 97) bit representation: BOM = Big endian (or) Little endian 00 48 00 65 00 6C 00 6C 00 6F (or) 48 00 65 00 6C
  6. 6. utf-8 is famous, because ● multi-byte encoding ● variable width encoding ● upto 4 byte code points are allowed by utf-8 ● mostly, No need BOM(8 bits) ● memory efficient How? for NON-ASCII bytes, 1st byte is reserved to indicate the no of bytes the char is using(eg.compression)
  7. 7. decoding Character to Numeric value(code point) conversion ● from <type 'str'> to <type 'unicode'> ● it throws maximum “UnicodeDecodeError:” (samples demo)
  8. 8. encoding ● Numeric value(code point) to Characters ● from <type 'unicode'> to <type 'str'> ● it throws maximum “UnicodeEncodeError:” (samples demo)
  9. 9. Rules to Remember… ● Decode early, Unicode everywhere, Encode late ● UTF-8 is the best guess for an encoding ● chardet.detect() ========================== in Python 3 this is solved… ● <type 'str'> is a Unicode object
  10. 10. How django handles? >>> def to_unicode( ... obj, encoding='utf-8'): ... if isinstance(obj, basestring): ... if not isinstance(obj, unicode): ... obj = unicode(obj, encoding) ... return obj smart_text(s, encoding='utf-8', strings_only=False, errors='strict') force_text(s, encoding='utf-8', strings_only=False, errors='strict') smart_bytes(s, encoding='utf-8',
  11. 11. How to set your python default encoding standard? import sys >>>reload(sys) >>>sys.setdefaultencoding(‘utf-8’) >>>sys.getdefaultencoding >>>’utf-8’ (or) # -*- coding: utf-8 -*- (tell to python you saved <mod_name.py> in utf-8)
  12. 12. Related python modules.. ● chardet.detect() ● unicodedata ● codecs
  13. 13. Thanks for your time Post your questions.
  14. 14. samples demo….
  15. 15. screenshot2

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