One byte converting to two when written to file

Question

I do not understand why my code is not working. I am writing some very simple code to write a single byte to a file.

with open("foo.txt", "w+", encoding='utf-8') as f:
    f.write('\x80')

As you can see below, it ends up writing two bytes when I only want to write one... Can anybody help?

You're setting the encoding to `utf-8` so it encodes it to `utf-8`. — tkausl, Oct 12 '20 at 10:07
@tkausl If I don't, it says "UnicodeEncodeError: 'charmap' codec can't encode character '\x80' in position 0: character maps to " — Professor Dragon, Oct 12 '20 at 10:08

obayhan · Accepted Answer · 2020-10-12T21:43:36.003

1

It is 2 bytes because of UTF-8 takes 2 byte places, if you decode it into UTF-16 you will see 4 bytes. They are more than 1 byte because you write it into UTF structure, not as a byte.

You have to open it in binary mode.

with open("foo.txt", "wb+") as f:
    f.write(b'\x80')

edited Oct 12 '20 at 21:43

answered Oct 12 '20 at 10:13

obayhan

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Ok, is there a pythonic way to convert `'\x80'` to `b'\x80'`? – Professor Dragon Oct 12 '20 at 10:15
depends on where did you get '\x80' from – obayhan Oct 12 '20 at 10:36
bytes([80]) is the trick It is up to you how to get the 80. – obayhan Oct 12 '20 at 10:42

One byte converting to two when written to file

1 Answers1