How to Split a Byte String into Lines?

Problem Formulation: Given a byte string that contains new-line characters '\n'. How to split the byte string into a list of lines?

Example: You want to transform the byte string b'your\nbyte\nstring' into the list of byte strings [b'your', b'byte', b'string'] using b'\n' as a newline separator.

Given:    b'your\nbyte\nstring'
Goal:     [b'your', b'byte', b'string']

Solution: To split a byte string into a list of lines—each line being a byte string itself—use the Bytes.split(delimiter) method and use the Bytes newline character b'\n' as a delimiter.

>>> s = b'your\nbyte\nstring'
>>> s.split(b'\n')
[b'your', b'byte', b'string']

Bytes objects look just like strings but are prefixed with the b symbol to indicate that they’re different to strings. Like strings, they are immutable sequences of single characters. However, in contrast to strings, the characters consist only of a single byte rather than multiple bytes. Thus, they’re based on ASCII encoding rather than based on more modern Unicode encoding.

Convert Bytestring to String and Split String

An alternative is to convert the byte string to a normal string first and then use the string.split() method on the converted data structure. In many cases, this is the recommended way because it ensures that you use modern encoding.

>>> s = b'your\nbyte\nstring'
>>> s = s.decode()
>>> s.split('\n')
['your', 'byte', 'string']

Troubleshooting

Note that you need to use a byte string as a delimiter or Python will throw a TypeError: a bytes-like object is required, not 'str'

>>> s = b'your\nbyte\nstring'
>>> s.split('\n')
Traceback (most recent call last):
  File "<pyshell#24>", line 1, in <module>
    s.split('\n')
TypeError: a bytes-like object is required, not 'str'

The fix is to use the Bytes delimiter b'\n' as shown before:

>>> s.split(b'\n')
[b'your', b'byte', b'string']