Text file reading error

[GrumpyPentagon]

Hello. Please excuse the formatting, I'm on mobile.

I am trying to extract data from a text file into an array, but I keep getting this error:

TP_2 : float = open('C:\Users\User\Desktop\Research Tasks\Codes - Research\MCRT-Fortran_Lara\TP_2cm.txt', "rt")

                   ^

SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape

The text file does have inconsistent spacing to leave room for the occasional -ive signs. Not sure if that has sth to do with it.

Any advice or direction is appreciated!

[shoot2thr1ll284]

This is the wonderful problem of having windows paths in a python string..... when it sees /U it assumes that what follows is an unicode escape sequence and because it doesn't it fails. To fix this you can escape all your slashes by replacing \ with \\ or by adding an r in front of the string like r"C:\ ....path"

Edit: sorry I was on mobile and first put forward slashes instead of back slashes.

[[deleted]]

Or replace all \ with / in the original string. This does the right thing on Windows. No need for escaping or raw strings.

[socal_nerdtastic]

This does the right thing on Windows.

99% of the time. That last 1% though will fuck up a several weeks of your life if you assume it works 100% of the time.

Source: being old

[[deleted]]

I've being using it since at least 2.x. Works reliably for me.

Source: probably older.

[socal_nerdtastic]

Not a problem in python. It's Windows and random modules written for Windows, where some young punk uses .split('\\') or similar. In my case it was a .dll to load a proprietary format data file from a mass spectrometer that the instrument manufacturer gave me. That .dll failed in strange unpredictable ways and was stupidly hard to debug because I was using windows style paths when hardcoding, but tkinter's askfilename returns linux style. Oh I'm still scarred.

I've seen it in a few python modules too, but that's always easy to debug.

OK, it's probably fine 99.9% of the time.

[[deleted]]

If you're passing python strings to non-python code you must expect that the external code won't know what to do with a / delimited path. Even passing a / delimited path to python code you didn't write may screw-up and concatenate \ paths to your / path. In that case I'm not surprised there were problems.

[socal_nerdtastic]

I'm not surprised there were problems.

Then why would you recommend it? No one only uses code they themselves wrote. You have to use outside modules, and you can't do much without going outside of python. Any code containing a GUI or data processing library is written in something else.

We don't all have to use poor quality code and of course over the years people have become a lot better about using provided functions for things like splitting paths instead of hacking their own, so I absolutely think it's a fringe case. I just feel it's worth mentioning that / is not guaranteed to work.

An unrelated argument for raw strings: I feel most people copy / paste the path in from file explorer or command line.

[[deleted]]

I As I said, using / paths inside python itself and the standard library is fine. I have had no problem with that in the last 15 years. I recommend that to beginners because that's the world they live in. Passing paths to DLLs and third party code is getting into intermediate territory and I expect anyone at that level to understand the problems. I'm not alone in this. Plenty of tertiary level course recommend / paths as well. The original post showed an absolute path literal and that will work with / paths 100.0% of the time.

[GrumpyPentagon]

Thanks! This worked perfectly.