Why encode () is used in python?

In this tutorial, we will learn about the Python String encode() method with the help of examples.

The encode() method returns an encoded version of the given string.

Example

title = 'Python Programming'

# change encoding to utf-8
print(title.encode())

# Output: b'Python Programming'

Syntax of String encode()

The syntax of encode() method is:

string.encode(encoding='UTF-8',errors='strict')

String encode() Parameters

By default, the encode() method doesn't require any parameters.

It returns an utf-8 encoded version of the string. In case of failure, it raises a UnicodeDecodeError exception.

However, it takes two parameters:

• encoding - the encoding type a string has to be encoded to
• errors - response when encoding fails. There are six types of error response
  • strict - default response which raises a UnicodeDecodeError exception on failure
  • ignore - ignores the unencodable unicode from the result
  • replace - replaces the unencodable unicode to a question mark ?
  • xmlcharrefreplace - inserts XML character reference instead of unencodable unicode
  • backslashreplace - inserts a \uNNNN escape sequence instead of unencodable unicode
  • namereplace - inserts a \N{...} escape sequence instead of unencodable unicode

Example 1: Encode to Default Utf-8 Encoding

# unicode string
string = 'pythön!'

# print string
print('The string is:', string)

# default encoding to utf-8
string_utf = string.encode()

# print result
print('The encoded version is:', string_utf)

Output

The string is: pythön!
The encoded version is: b'pyth\xc3\xb6n!'

Example 2: Encoding with error parameter

# unicode string
string = 'pythön!'

# print string
print('The string is:', string)

# ignore error
print('The encoded version (with ignore) is:', string.encode("ascii", "ignore"))

# replace error
print('The encoded version (with replace) is:', string.encode("ascii", "replace"))

Output

The string is: pythön!
The encoded version (with ignore) is: b'pythn!'
The encoded version (with replace) is: b'pyth?n!'

Note: Try different encoding and error parameters as well.

String Encoding

Since Python 3.0, strings are stored as Unicode, i.e. each character in the string is represented by a code point. So, each string is just a sequence of Unicode code points.

For efficient storage of these strings, the sequence of code points is converted into a set of bytes. The process is known as encoding.

There are various encodings present which treat a string differently. The popular encodings being utf-8, ascii, etc.

Using the string encode() method, you can convert unicode strings into any encodings supported by Python. By default, Python uses utf-8 encoding.

Python String encode() converts a string value into a collection of bytes, using an encoding scheme specified by the user.

Python String encode() Method Syntax:

Syntax: encode(encoding, errors)

Parameters: 

• encoding: Specifies the encoding on the basis of which encoding has to be performed. 
• errors: Decides how to handle the errors if they occur, e.g ‘strict’ raises Unicode error in case of exception and ‘ignore’ ignores the errors that occurred. There are six types of error response
  • strict – default response which raises a UnicodeDecodeError exception on failure
  • ignore – ignores the unencodable unicode from the result
  • replace – replaces the unencodable unicode to a question mark ?
  • xmlcharrefreplace – inserts XML character reference instead of unencodable unicode
  • backslashreplace – inserts a \uNNNN escape sequence instead of unencodable unicode
  • namereplace – inserts a \N{…} escape sequence instead of unencodable unicode

Return:  Returns the string in the encoded form

Python String encode() Method Example:

Python3

print("¶".encode('utf-8'))

Output:

b'\xc2\xb6'

Example 1: Code to print encoding schemes available

There are certain encoding schemes supported by Python String encode() method. We can get the supported encodings using the Python code below.

Python3

from encodings.aliases import aliases

print("The available encodings are : ")

print(aliases.keys())

Output: 

The available encodings are : 
dict_keys(['ibm039', 'iso_ir_226', '1140', 'iso_ir_110', '1252', 'iso_8859_8', 'iso_8859_3', 'iso_ir_166', 'cp367', 'uu', 'quotedprintable', 'ibm775', 'iso_8859_16_2001', 'ebcdic_cp_ch', 'gb2312_1980', 'ibm852', 'uhc', 'macgreek', '850', 'iso2022jp_2', 'hz_gb_2312', 'elot_928', 'iso8859_1', 'eucjp', 'iso_ir_199', 'ibm865', 'cspc862latinhebrew', '863', 'iso_8859_5', 'latin4', 'windows_1253', 'csisolatingreek', 'latin5', '855', 'windows_1256', 'rot13', 'ms1361', 'windows_1254', 'ibm863', 'iso_8859_14_1998', 'utf8_ucs2', '500', 'iso8859', '775', 'l7', 'l2', 'gb18030_2000', 'l9', 'utf_32be', 'iso_ir_100', 'iso_8859_4', 'iso_ir_157', 'csibm857', 'shiftjis2004', 'iso2022jp_1', 'iso_8859_2_1987', 'cyrillic', 'ibm861', 'ms950', 'ibm437', '866', 'csibm863', '932', 'iso_8859_14', 'cskoi8r', 'csptcp154', '852', 'maclatin2', 'sjis', 'korean', '865', 'u32', 'csshiftjis', 'dbcs', 'csibm037', 'csibm1026', 'bz2', 'quopri', '860', '1255', '861', 'iso_ir_127', 'iso_celtic', 'chinese', 'l8', '1258', 'u_jis', 'cspc850multilingual', 'iso_2022_jp_2', 'greek8', 'csibm861', '646', 'unicode_1_1_utf_7', 'ibm862', 'latin2', 'ecma_118', 'csisolatinarabic', 'zlib', 'iso2022jp_3', 'ksx1001', '858', 'hkscs', 'shiftjisx0213', 'base64', 'ibm857', 'maccentraleurope', 'latin7', 'ruscii', 'cp_is', 'iso_ir_101', 'us_ascii', 'hebrew', 'ansi_x3.4_1986', 'csiso2022jp', 'iso_8859_15', 'ibm860', 'ebcdic_cp_us', 'x_mac_simp_chinese', 'csibm855', '1250', 'maciceland', 'iso_ir_148', 'iso2022jp', 'u16', 'u7', 's_jisx0213', 'iso_8859_6_1987', 'csisolatinhebrew', 'csibm424', 'quoted_printable', 'utf_16le', 'tis260', 'utf', 'x_mac_trad_chinese', '1256', 'cp866u', 'jisx0213', 'csiso58gb231280', 'windows_1250', 'cp1361', 'kz_1048', 'asmo_708', 'utf_16be', 'ecma_114', 'eucjis2004', 'x_mac_japanese', 'utf8', 'iso_ir_6', 'cp_gr', '037', 'big5_tw', 'eucgb2312_cn', 'iso_2022_jp_3', 'euc_cn', 'iso_8859_13', 'iso_8859_5_1988', 'maccyrillic', 'ks_c_5601_1987', 'greek', 'ibm869', 'roman8', 'csibm500', 'ujis', 'arabic', 'strk1048_2002', '424', 'iso_8859_11_2001', 'l5', 'iso_646.irv_1991', '869', 'ibm855', 'eucjisx0213', 'latin1', 'csibm866', 'ibm864', 'big5_hkscs', 'sjis_2004', 'us', 'iso_8859_7', 'macturkish', 'iso_2022_jp_2004', '437', 'windows_1255', 's_jis_2004', 's_jis', '1257', 'ebcdic_cp_wt', 'iso2022jp_2004', 'ms949', 'utf32', 'shiftjis', 'latin', 'windows_1251', '1125', 'ks_x_1001', 'iso_8859_10_1992', 'mskanji', 'cyrillic_asian', 'ibm273', 'tis620', '1026', 'csiso2022kr', 'cspc775baltic', 'iso_ir_58', 'latin8', 'ibm424', 'iso_ir_126', 'ansi_x3.4_1968', 'windows_1257', 'windows_1252', '949', 'base_64', 'ms936', 'csisolatin2', 'utf7', 'iso646_us', 'macroman', '1253', '862', 'iso_8859_1_1987', 'csibm860', 'gb2312_80', 'latin10', 'ksc5601', 'iso_8859_10', 'utf8_ucs4', 'csisolatin4', 'ebcdic_cp_be', 'iso_8859_1', 'hzgb', 'ansi_x3_4_1968', 'ks_c_5601', 'l3', 'cspc8codepage437', 'iso_8859_7_1987', '8859', 'ibm500', 'ibm1026', 'iso_8859_6', 'csibm865', 'ibm866', 'windows_1258', 'iso_ir_138', 'l4', 'utf_32le', 'iso_8859_11', 'thai', '864', 'euc_jis2004', 'cp936', '1251', 'zip', 'unicodebigunmarked', 'csHPRoman8', 'csibm858', 'utf16', '936', 'ibm037', 'iso_8859_8_1988', '857', 'csibm869', 'ebcdic_cp_he', 'cp819', 'euccn', 'iso_8859_2', 'ms932', 'iso_2022_jp_1', 'iso_2022_kr', 'csisolatin6', 'iso_2022_jp', 'x_mac_korean', 'latin3', 'csbig5', 'hz_gb', 'csascii', 'u8', 'csisolatin5', 'csisolatincyrillic', 'ms_kanji', 'cspcp852', 'rk1048', 'iso2022jp_ext', 'csibm273', 'iso_2022_jp_ext', 'ibm858', 'ibm850', 'sjisx0213', 'tis_620_2529_1', 'l10', 'iso_ir_109', 'ibm1125', '1254', 'euckr', 'tis_620_0', 'l1', 'ibm819', 'iso2022kr', 'ibm367', '950', 'r8', 'hex', 'cp154', 'tis_620_2529_0', 'iso_8859_16', 'pt154', 'ebcdic_cp_ca', 'ibm1140', 'l6', 'csibm864', 'csisolatin1', 'csisolatin3', 'latin6', 'iso_8859_9_1989', 'iso_8859_3_1988', 'unicodelittleunmarked', 'macintosh', '273', 'latin9', 'iso_8859_4_1988', 'iso_8859_9', 'ebcdic_cp_nl', 'iso_ir_144'])

Example 2: Code to encode the string

Python3

string = "¶" 

print(string.encode('utf-8'))

Output:

b'\xc2\xb6'

Errors when using wrong encoding scheme

Example 1: Python String encode() method will raise UnicodeEncodeError if wrong encoding scheme is used

Python3

string = "¶" 

print(string.encode('ascii'))

Output:

UnicodeEncodeError: 'ascii' codec can't encode character '\xb6' in position 0: ordinal not in range(128)

Example 2: Using ‘errors’ parameter to ignore errors while encoding

Python String encode() method with errors parameter set to ‘ignore’ will ignore the errors in conversion of characters into specified encoding scheme.

Python3

string = "123-¶" 

print(string.encode('ascii', errors='ignore'))

Output:

b'123-'

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