MicroPython
byte/string representation query #9765
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Poking around in a .mpy file I noticed it's entrails display differently depending on how I open the file. |
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The .mpy file format is a binary file format, so it really only makes sense to open it using the binary ('rb') option. Otherwise, it opens it as a text file and decodes the contents as a UTF-8 string object (which could actually cause an error if the file contains invalid UTF-8 sequences). When opened as a binary file, Python reads the contents of the file as a bytes object instead of a string object. The way Python prints a bytes object looks very much like a string - there is just a |
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I want to understand how some bit patterns (like 0001 1111) look the same as a byte object or a string object (1f) but the objects representing other bit patterns (eg 1100 0110) are different (c6 for a bytes object but 06 for a string object)? |
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Because the string is the data interpreted/decoded as UTF-8, not individual bytes. UTF-8 can contain multi-byte characters. https://en.wikipedia.org/wiki/UTF-8 shows the bit patterns that will trigger this. |
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Ah yes, I get it now, tnx David. |
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The .mpy file format is a binary file format, so it really only makes sense to open it using the binary ('rb') option. Otherwise, it opens it as a text file and decodes the contents as a UTF-8 string object (which could actually cause an error if the file contains invalid UTF-8 sequences).
When opened as a binary file, Python reads the contents of the file as a bytes object instead of a string object. The way Python prints a bytes object looks very much like a string - there is just a
bbefore the opening".