Question

I’m uploading a csv/tsv file from a form in GAE, and I try to parse the file with python csv module.

Like describe here, uploaded files in GAE are strings.
So I treat my uploaded string a file-like object :

file = self.request.get('catalog')
catalog = csv.reader(StringIO.StringIO(file),dialect=csv.excel_tab)

But new lines in my files are not necessarily ‘\n’ (thanks to excel..), and it generated an error :
Error: new-line character seen in unquoted field – do you need to open the file in universal-newline mode?

Does anyone know how to use StringIO.StringIO to treat strings like files open in universal-newline?

Answer 1

How about:

file = self.request.get('catalog')
file  = '\n'.join(file.splitlines())
catalog = csv.reader(StringIO.StringIO(file),dialect=csv.excel_tab)

or as pointed out in the comments, csv.reader() supports input from a list, so:

file = self.request.get('catalog')
catalog = csv.reader(file.splitlines(),dialect=csv.excel_tab)

or if in the future request.get supports read modes:

file = self.request.get('catalog', 'rU')
catalog = csv.reader(StringIO.StringIO(file),dialect=csv.excel_tab)