Optionally importing unicode_literals from __future__

[shlomiassaf]

Hi,

Frist, thank you! Great work!

While working with some legacy libraries I sometimes unicode issues due to the use of unicode_literals

In one of the libraries we use object (dict) keys are used by the library as XPath path.
I did not see the internal implementation but I assume some logic is applied to tokenize, parse and process the "path" and the library does not expect to get a unicode string there and does not handle them.

When node_python_bridge.py does:

from __future__ import unicode_literals

It breaks.

For example, if I send the key default

root.something['defualt']

I will get an error:

badly formatted or nonexistent path (8): Bad key "d e f a u l t"

The library handled the unicode bytes as string without converting first, which somehow ended up with a space between every char pair.

I know that the problem is in the library I use and not in this library, but can it be set to optionally import unicode_literals, based on some option parameter?

Thanks!

For reference: http://python-future.org/unicode_literals.html

[munro]

Hmm yea from __future__ import unicode_literals should not be the default, since it isn't when not using this bridge! I added a broken test :D [1]

Maybe you can help me along, I was thinking perhaps dynamically setting from __future__ import ..., except it only works at the start of the file. So then I was thinking dynamically generate the node_python_bridge.py with the desired future imports... but then I realized that was really hacky.

Soo when I'm in ipython, I can set from __future__ import unicode_literals whenever I want—so ideally there's a way we can reproduce that behavior in node_python_bridge.py. Let me know if you find anything, I'll try to circle back when I have time to dig deeper.

[1] 0bae318

[munro]

Ahh, I figured it out. There's a module called code [1] that let's you spin up a REPL environment, this should be used in place of exec [2].

I gotta blast but I would greatly accept a PR!

[1] https://docs.python.org/2/library/code.html
[2] https://github.com/Submersible/node-python-bridge/blob/master/node_python_bridge.py#L80

[shlomiassaf]

Does code impact performance? Asking since it's aimed towards interactive interfaces... Anyway, didn't give it much thought but can you send args when running the script? This should enable conditional imports via option

…

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On Jun 24, 2017, at 3:56 AM, Ryan Munro ***@***.***> wrote: Ahh, I figured it out. There's a module called code [1] that let's you spin up a REPL environment, this should be used in place of exec [2]. [1] https://docs.python.org/2/library/code.html [2] https://github.com/Submersible/node-python-bridge/blob/master/node_python_bridge.py#L80 — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or mute the thread.

[munro]

Same performance! I dove into code and found out how it was working: it uses the codeop.Compile class which keeps track of any compiler flags that change. So when the compiler sees from __future__ import unicode_literals, it updates the compiler flags to parse Python strings as unicode instead of byte strings. yay!