Python | Character Encoding

Last Updated : 25 Nov, 2019

Finding the text which is having nonstandard character encoding is a very common step to perform in text processing.
All the text would have been from utf-8 or ASCII encoding ideally but this might not be the case always. So, in such cases when the encoding is not known, such non-encoded text has to be detected and the be converted to a standard encoding. So, this step is important before processing the text further.

Charade Installation :
For performing the detection and conversion of encoding, charade – a Python library is required. This module can be simply installed using sudo easy_install charade or pip install charade.

Let’s see the wraper function around the charade module.

Code : encoding.detect(string), to detect the encoding

# -*- coding: utf-8 -*- 
  
import charade 
def detect(s): 
      
    try: 
        # check it in the charade list 
        if isinstance(s, str): 
            return charade.detect(s.encode()) 
        # detecting the string 
          else: 
            return charade.detect(s) 
      
    # in case of error 
    # encode with 'utf -8' encoding 
    except UnicodeDecodeError: 
        return charade.detect(s.encode('utf-8')) 

The detect functions will return 2 attributes :

Confidence : the probability of charade being correct.
Encoding   : which encoding it is.

Code : encoding.convert(string) to convert the encoding.

# -*- coding: utf-8 -*- 
import charade 
  
def convert(s): 
      
    # if in the charade instance 
    if isinstance(s, str): 
        s = s.encode() 
      
    # retrieving the encoding information  
    # from the detect() output 
    encode = detect(s)['encoding'] 
      
    if encode == 'utf-8': 
        return s.decode() 
    else: 
        return s.decode(encoding)  

Code : Example

# importing library 
import encoding  
  
d1  = encoding.detect('geek') 
print ("d1 is encoded as  : ", d1) 
  
d2  = encoding.detect('ascii') 
print ("d2 is encoded as  : ", d2) 

Output :

d1 is encoded as : (confidence': 0.505, 'encoding': 'utf-8')
d2 is encoded as : ('confidence': 1.0, 'encoding': 'ascii')

detect() : It is a charade.detect() wrapper. It encodes the strings and handles the UnicodeDecodeError exceptions. It expects a bytes object so therefore the string is encoded before trying to detect the encoding.

convert() : It is a charade.convert() wrapper. It calls detect() first to get the encoding. Then, it returns a decoded string.

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