Why am I getting "invalid syntax" from an f-string?

Question

I cannot get f-strings to work in Python 3. I tried this at the REPL:

In [1]: state = "Washington"

In [2]: state
Out[2]: 'Washington'

In [3]: my_message = f"I live in {state}"
File "<ipython-input-3-d004dd9e0255>", line 1
my_message = f"I live in {state}"
                                ^
SyntaxError: invalid syntax

I figured my machine was defaulting to python 2, but a quick check reveals:

Python 3.5.2 (default, Nov 17 2016, 17:05:23) 
Type "copyright", "credits" or "license" for more information.

IPython 5.2.2 -- An enhanced Interactive Python.

What is wrong, and how do I fix it?

What version of python were the others using? You seem to have answered your own question. https://docs.python.org/3/whatsnew/3.6.html#pep-498-formatted-string-literals — Josh Lee, Feb 09 '17 at 01:42
@yeputons, avoid answering questions in the comments. Add an answer. — Adrian Sanguineti, Feb 09 '17 at 02:24
It's a close call, but I think the answers for the other question were slightly better overall, so I'm making that one the canonical. — Karl Knechtel, Jan 22 '23 at 02:59

score 95 · Accepted Answer · answered Feb 09 '17 at 02:35

As suggested by Josh Lee in the comment section, that kind of string interpolation was added in Python 3.6 only, see What’s New In Python 3.6 (here it's called "PEP 498: Formatted string literals").

You, however, seems to be using Python 3.5.2, which does not support that syntax.

score 21 · Answer 2 · answered Jan 21 '20 at 07:11

21

This is a pretty old question and not sure if answered somewhere else, but ran into same problem and landed on some confusing pages. Figured out a couple of minutes later. Below line should work.

my_message = "I live in {}".format(state)

.format works for 3.5. Documenting it here for someone who may need it for similar issue.

answered Jan 21 '20 at 07:11

Ritesh Kankonkar

363
3
12

Out of everything I tried, this was the only thing that worked. Thanks! – Farid Jan 21 '20 at 07:56

score -13 · Answer 3 · answered Sep 06 '20 at 04:53

-13

What worked for me (in python 3.8.5 in sublime) was removing the f.

message = "I live in {state}"

I find it easier than .format(state)

answered Sep 06 '20 at 04:53

hamstercoding

7
6

11

Well, it "works" in the sense that it doesn't give a syntax error... whether it does what was intended is another question. – fool4jesus Sep 08 '20 at 12:54
This will not throw an error but it will not interpolate your `state` value in the string output. – Sven E Apr 20 '22 at 17:21

Why am I getting "invalid syntax" from an f-string?

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