How do i decode a number in python?

View Discussion

Nội dung chính Show

Description
Return Value
How do you decode a value in Python?
What does decode () do in Python?
How do you decode numbers to letters in Python?
What is the purpose of encode () and decode () method in Python?

Improve Article

Save Article

Read

Discuss

View Discussion

Improve Article

Save Article

decode() is a method specified in Strings in Python 2.
This method is used to convert from one encoding scheme, in which argument string is encoded to the desired encoding scheme. This works opposite to the encode. It accepts the encoding of the encoding string to decode it and returns the original string.

Syntax : decode(encoding, error)
Parameters :
encoding : Specifies the encoding on the basis of which decoding has to be performed.
error : Decides how to handle the errors if they occur, e.g ‘strict’ raises Unicode error in case of exception and ‘ignore’ ignores the errors occurred.
Returns : Returns the original string from the encoded string.

Code #1 : Code to decode the string

str = "geeksforgeeks"

str_enc = str.encode(encodeing='utf8')

print ("The encoded string in base64 format is : ",)

print (str_enc )

print ("The decoded string is : ",)

print (str_enc.decode('utf8', 'strict'))

Output:

The encoded string in base64 format is :  Z2Vla3Nmb3JnZWVrcw==

The decoded string is :  geeksforgeeks

Application :
Encoding and decoding together can be used in the simple applications of storing passwords in the back end and many other applications like cryptography which deals with keeping the information confidential.
A small demonstration of the password application is depicted below.

Code #2 : Code to demonstrate application of encode-decode

user = "geeksforgeeks"

passw = "i_lv_coding"

passw = passw.encode('base64', 'strict')

user_login = "geeksforgeeks"

pass_wrong = "geeksforgeeks"

print ("Password entered : " + pass_wrong )

if(pass_wrong == passw.decode('base64', 'strict')):

print ("You are logged in !!")

else : print ("Wrong Password !!")

print( '\r')

pass_right = "i_lv_coding"

print ("Password entered : " + pass_right )

if(pass_right == passw.decode('base64', 'strict')):

print ("You are logged in !!")

else :

print ("Wrong Password !!")

Output:

Password entered : geeksforgeeks
Wrong Password!!

Password entered : i_lv_coding
You are logged in!!

Description

Python string method decode() decodes the string using the codec registered for encoding. It defaults to the default string encoding.

Syntax

Str.decode(encoding='UTF-8',errors='strict')

Parameters

encoding − This is the encodings to be used. For a list of all encoding schemes please visit: Standard Encodings.
errors − This may be given to set a different error handling scheme. The default for errors is 'strict', meaning that encoding errors raise a UnicodeError. Other possible values are 'ignore', 'replace', 'xmlcharrefreplace', 'backslashreplace' and any other name registered via codecs.register_error().

Return Value

Decoded string.

Example

#!/usr/bin/python

Str = "this is string example....wow!!!";
Str = Str.encode('base64','strict');

print "Encoded String: " + Str
print "Decoded String: " + Str.decode('base64','strict')

Result

Encoded String: dGhpcyBpcyBzdHJpbmcgZXhhbXBsZS4uLi53b3chISE=
Decoded String: this is string example....wow!!!

python_strings.htm

How do you decode a value in Python?

decode() is a method specified in Strings in Python 2. This method is used to convert from one encoding scheme, in which argument string is encoded to the desired encoding scheme. This works opposite to the encode. It accepts the encoding of the encoding string to decode it and returns the original string.

What does decode () do in Python?

Python bytes decode() function is used to convert bytes to string object. Both these functions allow us to specify the error handling scheme to use for encoding/decoding errors. The default is 'strict' meaning that encoding errors raise a UnicodeEncodeError.

How do you decode numbers to letters in Python?

Decode Ways in Python.

x := s[i] as integer, y := substring of s from index i – 1 to i + 1 as integer..

if x >= 1 and y <= 9, then dp[i] := dp[i] + dp[i – 1].

if y >= 10 and y <= 26. if i – 2 >= 0, then dp[i] := dp[i] + dp[i – 2], otherwise increase dp[i] by 1..

What is the purpose of encode () and decode () method in Python?

Since encode() converts a string to bytes, decode() simply does the reverse. This shows that decode() converts bytes to a Python string. Similar to those of encode() , the decoding parameter decides the type of encoding from which the byte sequence is decoded.