Invalid syntax error when using f-string in Python 3.6

Question

I've run into this weird error and I'm wondering whether anyone has a clue what's going on.

I'm trying to print the minimal date from a date column in Pandas series. However, the following is raising an invalid syntax error:

print(f'{df_raw['POSTING_DATE'].min()}')

This does work, though:

min_date = df_raw['POSTING_DATE'].min()
print(f'{min_date}')

Using .format() also works. Obviously I can use a workaround here but I was just wondering why the f-string syntax doesn't work in this case. I thought the f-strings should be able to handle similar expressions. I'm using Python 3.6.9.

Does this answer your question? [Invalid Syntax when F' string dictionary](https://stackoverflow.com/questions/57876137/invalid-syntax-when-f-string-dictionary) — user202729, Feb 12 '21 at 13:33
Also https://stackoverflow.com/questions/53609639/invalid-syntax-expression-returning-a-string-in-f-string — user202729, Feb 12 '21 at 13:34

Krishna Chaurasia · Answer 1 · 2021-02-12T13:33:11.000

4

Use " as:

print(f"{df_raw['POSTING_DATE'].min()}")

Update:

Ideally, we could use \ to escape quotes but f-strings does not support using \ in it so this wouldn't work with f-strings

print(f'{df_raw[\'POSTING_DATE\'].min()}')

edited Feb 12 '21 at 13:33

answered Feb 12 '21 at 13:29

Krishna Chaurasia

8,924
6
22
35

Your first suggestion will not work. You can't escape quotes inside an f-string expression. – khelwood Feb 12 '21 at 13:32
Yes, I realized after posting, I have updated the answer. – Krishna Chaurasia Feb 12 '21 at 13:33
Ooooh so that's what it was. Can't believe I didn't think of that. Thanks! – styx_oarsman Feb 12 '21 at 13:40

Invalid syntax error when using f-string in Python 3.6

1 Answers1