python为什么要在\\ i中添加另一个反斜杠

Question

I thought I understood backslash escaping, but I don't get this behaviour:

foo = '\t'

gives the same string (ie \\t ) when I type foo in the Python interpreter, whereas

bar = '\i'

gives \\\\i . What's happening? I want to have just \\i , because I'm writing it to a .tex file that I'm then compiling, and this seems to mess up the LaTeX commands.

Edit: it was in fact not this that was messing up my latex, as the answers below show

Answer 1

"\\t" is a tab (one character), "\\i" contains two characters, the first of which is escaped by __repr__ .

In [51]: len("\t")
Out[51]: 1

In [52]: len("\i")
Out[52]: 2

Edit: If you write to a file, your output will be fine.

with open("o.tex", "w") as o:
    o.write(">>>\t|\i|\t<<<\n")

The content of o.tex will then be

>>>     |\i|    <<<

You can see the two tabs \\t as whitespace while all other characters are as-is.