Lexer在Python中输出“ TypeError：write（）参数必须为str，而不是字节”。 我究竟做错了什么？

Question

I am sorry if this is only a dumb mistake, because I have little experience with Python, or programming at all. pickle.dump(code, output) does not like the arguments I am giving it. How do I resolve this?

Here is the piece of sample code that outputs my file to lexer_output.txt:

global output
output = open ("C:\\Users\Asher\Documents\BUSlang\lexer_output", "w")
pickle.dump(code, output)

The error is

"TypeError: write() argument must be str, not bytes"

The variable code is defined earlier in the script at code=meta.read() . There were no other errors.

Answer 1

The error message is not very helpful. After some trial and error I got it to work with

output = open("C:\\Users\Asher\Documents\BUSlang\lexer_output", "wb")

ie the output file you want to write to must be opened in binary mode.

Another note: I'm not sure why you are using global output , in your sample code it is not needed.

Answer 2

From pickle.dump() docs :

The file argument must have a write() method that accepts a single bytes argument.

"w" file mode implies that write() accepts str objects, not bytes , pass "wb" instead.

You should have passed a binary file instead of the file opened in the text mode.