Python csv.DictReader: parse string?

Question

I am downloading a CSV file directly from a URL using requests.

How can I parse the resulting string with csv.DictReader?

Right now I have this:

r = requests.get(url) reader_list = csv.DictReader(r.text) print reader_list.fieldnames for row in reader_list:     print row 

But I just get ['r'] as the result of fieldnames, and then all kinds of weird things from print row.

Answer 1

From the documentation of csv, the first argument to csv.reader or csv.DictReader is csvfile -

csvfile can be any object which supports the iterator protocol and returns a string each time its __next__() method is called — file objects and list objects are both suitable.

In your case when you give the string as the direct input for the csv.DictReader() , the __next__() call on that string only provides a single character, and hence that becomes the header, and then __next__() is continuously called to get each row.

Hence, you need to either provide an in-memory stream of strings using io.StringIO:

>>> import csv >>> s = """a,b,c ... 1,2,3 ... 4,5,6 ... 7,8,9""" >>> import io >>> reader_list = csv.DictReader(io.StringIO(s)) >>> print(reader_list.fieldnames) ['a', 'b', 'c'] >>> for row in reader_list: ...     print(row) ...  {'a': '1', 'b': '2', 'c': '3'} {'a': '4', 'b': '5', 'c': '6'} {'a': '7', 'b': '8', 'c': '9'} 

or a list of lines using str.splitlines:

>>> reader_list = csv.DictReader(s.splitlines()) >>> print(reader_list.fieldnames) ['a', 'b', 'c'] >>> for row in reader_list: ...     print(row) ...  {'a': '1', 'b': '2', 'c': '3'} {'a': '4', 'b': '5', 'c': '6'} {'a': '7', 'b': '8', 'c': '9'}