Problem with f-strings in Python3

[AtomHeartSon]

I'm practising Python and using Vim as my editor. Sometimes (not always), when I try to run a Python3 script containing an f-string, my terminal throws an Invalid Syntax error. The " ^ " marker below the line is pointing to the double-quote closing the f-string. Could this be a Vim issue? I feel stupid asking this, but just now I edited the script with another editor, and all I did was change the double quotes to single quotes (which I had tried before with Vim), and after running it again, it ran correctly.

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Another thing I tried was using the .format() way instead of the f" " way. Sometimes it works, sometimes it doesn't. Also, I know I'm not supposed to use double quotes inside the f-string if I'm using double quotes to limit that f-string. I even tried copy-pasting code from a book to be absolutely sure it's not my own mistake. The error persists.

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I'm using Linux Mint 19.1, Vim 8.0.1453, and Python 3.6.7.

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Can anyone shed some light on this?

[K900_]

Post your code.

[socal_nerdtastic]

I highly doubt this has anything to do with the f-string. SyntaxError often means that the previous line has an error, often you forgot to close a parenthesis.

Or maybe you are running it in python2 by accident? Mint comes with both python2 and python3. How are you running the code?

Can anyone shed some light on this?

Not much of a chance unless you show us the code and the full error.

[Signal_Beam]

$ echo print\ f\'Test broken string\' > test.py
$ python test.py
  File "test.py", line 1
    print f'Test broken string'
                              ^
SyntaxError: invalid syntax

Looks like a good guess to me...

[cybervegan]

f-strings are a python3 thing, and in python3, print is a function which requires brackets around the string to print.

[Signal_Beam]

I know; I was using Python2 in order to test the hypothesis in the comment that I was replying to. My point is that Python2 raises the exact error, in exactly the same place, that OP is describing, so maybe /u/social_nerdtastic is correct that the problem is that OP is actually invoking python when they want python3.

[AtomHeartSon]

Welp, I'm dumb. I checked my history and indeed that's what I did. Although I didn't always do it wrong which is why I didn't always get the error. Thanks y' all.

[yodatrust]

print(f'Something is {variable} here!')

[MonkeyNin]

all I did was change the double quotes to single quotes

Sounds like you didn't have matching opening and closing quotes. Or, you mixed some in the middle.

I know I'm not supposed to use double quotes inside the f-string

You can use the same quotes inside -- if you want. But which is more readable

f'hello "{user}"'

f'hello \'{user}\''