Reading bytes from file without specifying encoding in Python 3

Question

In Python 2, the following will happily load the first two bytes from a binary file:

with open(file_name) as f:
    b = f.read(2)

However, in Python 3, the same might result in e.g.:

UnicodeDecodeError: 'utf-8' codec can't decode byte 2: invalid start byte

Which brings me to the question: how to read N raw bytes from a file in Python 3 without specifying an encoding?

user2357112 · Accepted Answer · 2015-05-27 23:13:47Z

4

Specify binary mode:

with open(file_name, 'rb') as f:

You should do that in Python 2, too, unless you want bugs like CRLFs becoming LFs in your binary file.

answered May 27, 2015 at 23:13

user2357112

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