Cannot parse strings from list into floats, getting ValueError

Question

I am writing short pygame script and I need to parse values from .cfg file, but I am not very experienced in python and I am getting ValueError and have no idea why it cannot parse the string.

I have tried writing a method to take the string and convert it to an int, if it fails convert it to float but that didn't work.

Here's the code:

def _file_read(self):
        with open(os.path.join(sys.path[0], "planets.cfg")) as config:
            lines = [line.replace(';', '').replace('{', '').replace('}', '').split() for line in config]
            for j in range(len(lines)):
                self.name.append(lines[j][0])
                self.radius.append(float(lines[j][1]))
                self.distance.append(float(lines[j][2]))
                self.speed.append(float(lines[j][3]))
                self.color.append(lines[j][4])

Here is what is inside the planets.cfg file, don't mind the values, they are made up for testing purposes.

Earth {123; 321; 0.005; (0,255,0)}
Mars {432; 234; 0.004; (255,0,0)}

I need to have a float that I can pass to a mathematical formula, but the ValueError likes the floats place a bit more.

Any idea how to handle that? I will be very grateful for any help or explanation why this error happens :)

Oh and here is the error it outputs:

  File "C:/Users/Jakub/PycharmProjects/untitled/kruznice.py", line 35 in _file_read
  self.radius.append(float(lines[j][1])) ValueError: could not convert   string to float: 'radius'

EDIT Added error message, yeah, I am a really scatterbrained person.

EDIT #2 (Solution): So after a while I found the solution and it basically has NOTHING to do with code being wrong. I have had string values on line 2 in the planets.cfg file and somehow I forgot to save it, and was constantly thinking I am using the newer version with integers and floats only. Yes. Stupid mistakes happen. And I make lot of them.

Rakesh · Accepted Answer · 2019-03-29 12:20:59Z

1

The error is from self.color.append(float(lines[j][4])) You are trying to convert a tuple to float

Use ast module to convert it to a tuple

Ex:

from ast import literal_eval

def _file_read(self):
    with open(os.path.join(sys.path[0], "planets.cfg")) as config:
        lines = [line.replace(';', '').replace('{', '').replace('}', '').split() for line in config]
        for j in lines:
            self.name.append(j[0])
            self.radius.append(float(j[1]))
            self.distance.append(float(j[2]))
            self.speed.append(float(j[3]))
            self.color.append(literal_eval(j[4]))

answered Mar 29, 2019 at 12:20

Rakesh

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3 Comments

kuskus Over a year ago

Thank you. This was a mistake, I maybe left the float in there in a hurry. I don't want to parse that. Sorry. I get ValueError at radius which is clearly an integer or can be a float. I'm sorry for the confusion I'll fix it right away

kuskus Over a year ago

Sure, added to the main post ;)

kuskus Over a year ago

Thank you for the literal_eval, had to use it anyway on converting the string to a RGB tuple ;)

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