How to use f method on a variable for inserting text

Question

Suppose I have this example

word1 = "filled"
word2 = "verbs"
word3 = "nouns"
test_string1 = f"I {word1} in these {word2} and {word3}."

If you print this, you get

I filled in these verbs and nouns.

Now, suppose Instead I first do this

test_string2 = "I {word1} in these {word2} and {word3}."

Is there a way to fill in this second string with the corresponding variables?

I tried

test_string3 = f test_string2

But that didn't work.

  File "<ipython-input-25-d1b8ffc3fdb5>", line 1
    test_string3 = f test_string2
                                ^
SyntaxError: invalid syntax

Does this answer your question? [Is it possible to reuse an f-string as it is possible with a string and format?](https://stackoverflow.com/questions/52248776/is-it-possible-to-reuse-an-f-string-as-it-is-possible-with-a-string-and-format) — Julia, Feb 15 '22 at 15:29
`f` isn't a function. For what you want to do, you can use `.format()` str method. — C14L, Feb 15 '22 at 15:29

score 3 · Answer 1 · answered Feb 15 '22 at 15:33

3

You can't. Closest you can get is:

word1 = "filled"
word2 = "verbs"
word3 = "nouns"
test_string1 = "I {word1} in these {word2} and {word3}.".format(**locals())

answered Feb 15 '22 at 15:33

bvan

score 2 · Answer 2 · answered Feb 15 '22 at 15:31

2

Use test_string2.format(word1=word1, word2=word2, word3=word3).

answered Feb 15 '22 at 15:31

timgeb

2 Answers2