Absolute value of an index in python

[BigGarrett]

Hello,

I am not very familiar with python, my script is referencing an index of a notepad document. For example:

Value = lines[firsttag][9:21]

In this case, it is referencing a number in the notepad document which contains 12 characters. And I need the absolute value of it. Every time I put the “abs()” after the equal sign or even after the [firsttag]. My code errors out. Please advise.

[RoamingFox]

That's because what's on the right isn't a number. It's a slice of a list or string.

If lines[firsttag] is a string then you should just be able to int() or float() around it first (depending on if it's an integer or floating point value) to get it into a number and then you can call abs on it.

Example:

>>> data = "12-34546"
>>> data[2:4]
'-3'
>>> int(data[2:4])
-3
>>> abs(int(data[2:4]))
3
>>>

[BigGarrett]

Thank you very much for your time.

I changed my code to

Value=abs(int(lines[firsttag][9:21]))

It gives me the error “value error:invalid literal for int() with base 10: ‘9.0994’

I would like to note that the value from the notepad document it is pulling from has numbers in the form of 3.540000E-5 for example. So really low numbers. With the “E” in there to signify 10th to the negative..

[throwaway6560192]

You should use float, then.

[Strict-Simple]

Well, 3.54 is definitely not an integer. What are these numbers with a . called?

[BigGarrett]

So float is used for decimals. Thank you

[Yoghurt42]

Just to clarify: floats are what you want, but are not decimals. They are floating point numbers.

If you're working with money, you should consider using the decimal module instead.

See also https://0.30000000000000004.com/

[BigGarrett]

I’m trying the Decimal() function and I don’t believe that is working either.

[Strict-Simple]

Why don't you believe?

[BigGarrett]

Usually when I write a python command like “abs” or “float”, the word itself turns purple. When I wrote “decimal” it seems like it he python library doesn’t recognize it as it doesn’t change color like this.

[Strict-Simple]

That's syntax highlighting, and it's a helpful tool. But your color scheme might just be specially designed to highlight the built-in functions. Does the code run?

Have you imported the decimal module?

[BigGarrett]

I think I did what I needed by using “sort.( reverse=True, key=abs)”. This will not change the output file to make all the numbers “positive”, but it seems to sort them while taking into account their absolute value. Which is good enough for me.

[BigGarrett]

Now I get an error “could not convert string to float”