File a.py:

------------------------------------
print("foo", end='bar') # ParseError
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I think the error is caused by arguments in the Python 3 print() function (e.g. end, sep) that are not ignored by 2to3, and (possibly) treated like Python 2 code.

Console stuff:

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$ pip install 2to3
Requirement already satisfied: 2to3 in .\python37\lib\site-packages (1.0)

$ 2to3 .\a.py
...
RefactoringTool: Can't parse .\a.py: ParseError: bad input: type=22, value='=', context=('', (1, 16))
...
---------------------------------------------------

I'm not sure I understand the report: 2to3 expects a valid Python 2 file as input, and the file a.py isn't a valid Python 2 file: the `print` line is a SyntaxError in the absence of a `from __future__ import print_function`.

So yes, this *is* being treated like Python 2 code, but that's what 2to3 is designed to do.

Can you say what you expected to happen here?

I was expecting that like other Python 3 code, since it is already in Python 3, it would not parse it like Python 2.

I'm still confused: the main purpose of 2to3 is to take Python 2 code and turn it into Python 3 code. The docs[1] are fairly unambiguous here:

> 2to3 is a Python program that reads Python 2.x source code and applies a series of fixers to transform it into valid Python 3.x code.

So expecting 2to3 *not* to parse code as though it's Python 2 code seem odd.

[1] https://docs.python.org/3.7/library/2to3.html

Closing. 2to3 is working as designed here.