Super simple KG to LBS conveter

Question

just got into python, any advice why these simple lines sends me an error?

# ---------------- WEIGHT CONVERTER ----------------#

_userWeight = input("Weight [KG]: ")
_userLbs = int(_userWeight) * 2.2
print(int(_userWeight) + "[KG] = " + int(_userLbs) + "[lbs]")

You cannot concatenate str and int. Use f-strings or str.format() method. — buran, Jan 23 '22 at 08:38
See [How do I ask a good question?](https://stackoverflow.com/help/how-to-ask) — martineau, Jan 23 '22 at 10:16

score 2 · Accepted Answer · answered Jan 23 '22 at 08:40

2

  _userWeight = input("Weight [KG]: ")
  _userLbs = int(_userWeight) * 2.2 
  print(int(_userWeight) , "[KG] = " , int(_userLbs) , "[lbs]")

Remove the '+' and use a ','

Output:

Weight [KG]: 50

50 [KG] = 110 [lbs]

answered Jan 23 '22 at 08:40

PSR

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Thanks you for the quick solution. so in which cases do I use the + signs when working with strings and other variables? – Kennyair Jan 23 '22 at 08:42
only when everythin you print is the same exact data type – PSR Jan 23 '22 at 08:43
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A '+' is basically a concatenate, and you cannot concatenate diff. data types – PSR Jan 23 '22 at 08:44

Solebay Sharp · Answer 2 · 2022-01-23T09:06:49.897

0

You cannot concatenate both string and integer data types.

You can however present the values as a string:

_userWeight = input("Weight [KG]: ")
_userLbs = int(_userWeight) * 2.2
print(str(_userWeight) + "[KG] = " + str(_userLbs) + "[lbs]")

# 80[KG] = 176.0[lbs]

edited Jan 23 '22 at 09:06

answered Jan 23 '22 at 08:39

Solebay Sharp

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_mix_ is unclear term in this case – buran Jan 23 '22 at 08:40
_You cannot print both strings and integers on a single lin_ this becomes worse with every iteration... – buran Jan 23 '22 at 08:44
Well I amended it prior. Is it now tolerable? – Solebay Sharp Jan 23 '22 at 08:45
It's not at all about printing. It's about **concatenating** `str` and `int` objects. They can as well try to construct a `str` by concatenating `str` and `int` and bind it to a name and it will fail all the same. e.g. `result = int(_userWeight) + "[KG] = " + int(_userLbs) + "[lbs]"`. And it's completly different story if they need `int()` at all. – buran Jan 23 '22 at 08:47
Yeah.. it is absolutely about printing though. That's actually the crux of the question. – Solebay Sharp Jan 23 '22 at 08:49
No, the problem and question is about the concatenating. It just happens that they construct the string and print it in one-line. It may well be a return statement in a function. – buran Jan 23 '22 at 08:50
'It may well be' cuts in any number of directions. – Solebay Sharp Jan 23 '22 at 08:54
2

Just look at the other answer by @PSR and you will learn how to print `str` and `int` in one line. Of course `f-string` and `str.format()` are always preferable. – buran Jan 23 '22 at 08:56
Can't argue with that. – Solebay Sharp Jan 23 '22 at 09:16

Super simple KG to LBS conveter

2 Answers2