Python: extract floats from txt files

Question

I have this txt file:

TP 0.8329

And i tried to extract that float after "TP" using the following code:

def definir_operacao():
    end = 0
    oper = []
    for x in range(len(lines[0])):
        if(lines[0][x] == " "):
            end += 1
        elif(end == 1):
            oper.append(int(lines[0][x]))
    str2 = ''.join(oper)
    return str2


ci = definir_operacao()
print(ci)

But i get a empty variable as response, so i guess i'm making something wrong, can anyone help me?

Can you include the complete code you are working on? Including the part where you read the file. — DeusDev, Jul 17 '21 at 01:52
if this is some kind of config file meant to be read by code, use a python file, yaml, ini, or other "code friendly" format. If it is a spreadsheet, use pandas. Reading data is a common task, so the first thing to find are the shiny tools that already exist to make your life easier — anon01, Jul 17 '21 at 01:57

score 0 · Answer 1 · answered Jul 17 '21 at 01:53

0

Just do this one-liner instead:

ci = float(lines[0].split()[1])

And now:

print(ci)

Would give:

0.8329

answered Jul 17 '21 at 01:53

U13-Forward

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score 0 · Answer 2 · answered Jul 17 '21 at 02:07

You're checking that whether you get an " ", and if so you're appending the exact same " " with oper. See this segment again:

if(lines[0][x] == " "):
        end += 1
elif(end == 1):
        oper.append(int(lines[0][x]))

That is why you're getting empty as response.

just split the line on the basis of " " and take the second value from the splitting result. Don't forget to cast it to float. That will give you what you want.

res = float(lines[0].split(" ")[1])

You can just use split() too as @U11-Forward mentioned, because default separator is whitespace.

Python: extract floats from txt files

2 Answers2