csv import with Python's QUOTE_NONNUMERIC not working as expected

Question

I can't figure this out, maybe I'm getting blind for looking to long on the same stuff...

I have this kind of lines in a CSV file:

""BIN"",""Afg"",""SONIC/SONIC JET/"",1,8.9095,""Due to the dynamic nature of the exemptions granted to many operators, the Contract Price does not reflect V.A.T. / G.S.T., Mineral Oil Taxes, Federal Excise Taxes or other taxes to which an operator may be exempt.  Please contact your salesperson or World Fuel Services if you require assistance in generating a fuel price estimate."",""N/A"",""01-NOV-2013"

Which I'm trying to import like this:

data = csv.DictReader(open(newdatafile), delimiter=',', quoting=csv.QUOTE_NONNUMERIC)
data.fieldnames = [
    'iata', 'country', 'fbo', 'quantity', 'price', 'remarks', 'special', 'validdate'
]

for row in data:
    fuelentry = FuelPriceImport()
    fuelentry.iata = row['iata']
    fuelentry.fbo = row['fbo']
    fuelentry.min_quantity = row['quantity']
    fuelentry.net_price_liter = row['price']
    fuelentry.remarks = row['remarks']
    fuelentry.save()

When I run this piece of code, it always complains about:

could not convert string to float: the Contract Price does not reflect V.A.T. / G.S.T.

Which is obviously directly after the comma within the double quoted string.

Shouldn't QUOTE_NONNUMERIC avoid exactly this, as the whole text is within double quotes?

Answer 1

Your input format uses doubled quotes, which is the CSV equivalent of escaping the quotes.

You'll have to replace doubled quotes with single quotes; you can do this on-the-fly with a wrapper generator:

def undoublequotes(fobject):
    for line in fobject:
        yield line.replace('""', '"')

This does assume that the column data itself does not contain doubled quotes.

Demo:

>>> import csv
>>> from pprint import pprint
>>> def undoublequotes(fobject):
...     for line in fobject:
...         yield line.replace('""', '"')
... 
>>> sample = '''\
... ""BIN"",""Afg"",""SONIC/SONIC JET/"",1,8.9095,""Due to the dynamic nature of the exemptions granted to many operators, the Contract Price does not reflect V.A.T. / G.S.T., Mineral Oil Taxes, Federal Excise Taxes or other taxes to which an operator may be exempt.  Please contact your salesperson or World Fuel Services if you require assistance in generating a fuel price estimate."",""N/A"",""01-NOV-2013"
... '''
>>> reader = csv.reader(undoublequotes(sample.splitlines(True)),
...                     quoting=csv.QUOTE_NONNUMERIC)
>>> pprint(next(reader))
['BIN',
 'Afg',
 'SONIC/SONIC JET/',
 1.0,
 8.9095,
 'Due to the dynamic nature of the exemptions granted to many operators, the Contract Price does not reflect V.A.T. / G.S.T., Mineral Oil Taxes, Federal Excise Taxes or other taxes to which an operator may be exempt.  Please contact your salesperson or World Fuel Services if you require assistance in generating a fuel price estimate.',
 'N/A',
 '01-NOV-2013']