ValueError: could not convert string to float: '" "'

Question

I have some values is csv file and In csv file some values are numeric and some are string number. Example of csv file:

1,"1151226468812.22",100,1,467,999.00,999.95,15,1,999.00,999.95,998.50,999.95,15,999.01,1396,34,06092016091501.444,1394627.25
2,"1151226468812.11",100,1,467,999.00,1000.00,1605,3,999.00,1000.00,998.50,1000.00,5,999.03,1426,37,06092016091502.111,1424626.50

So I wnated to convert string to float. So here is my code:

datareader = csv.reader(datafile, delimiter=",", quoting= csv.QUOTE_NONE)

    names =  []
    names.append("local_timestamp")
    names.append("nse_timestamp")
for row in datareader:
        data = dict()
        data.update(local_timestamp = row[0])
        data.update(nse_timestamp = float(row[1]))

But it return value error.

ValueError: could not convert string to float: '"1151226468812.22"'

Answer 1

The problem is that your string is not just '1151226468812.22', but it is '"1151226468812.22"'. It also contains speech marks ("). This means that before you convert this to a float, you need to remove the leading and trailing speech marks. Luckily, Python has a very handy string method .strip() to do this for you.

string.strip(s) will return a string that has the leading and ending 's' characters removed

For example:

myString = "#hello#".strip("#")

In this code, myString would be just 'hello'

In this case, you want to strip row[1] of the leading and trailing " characters. You can do this very easily:

row[1].strip("\"")