Unicode DictReader and DictWriter

data.csv

gistfile1.py

#!/usr/bin/env python

import csv, codecs, cStringIO, sys

class UTF8Recoder:
    """
    Iterator that reads an encoded stream and reencodes the input to UTF-8
    """
    def __init__(self, f, encoding):
        self.reader = codecs.getreader(encoding)(f)

    def __iter__(self):
        return self

    def next(self):
        return self.reader.next().encode("utf-8")

class UnicodeDictReader:
    """
    A CSV reader which will iterate over lines in the CSV file "f",
    which is encoded in the given encoding.
    """

    def __init__(self, f, dialect=csv.excel, encoding="utf-8", **kwds):
        f = UTF8Recoder(f, encoding)
        self.reader = csv.reader(f, dialect=dialect, **kwds)
        self.header = self.reader.next()

    def next(self):
        row = self.reader.next()
        vals = [unicode(s, "utf-8") for s in row]
        return dict((self.header[x], vals[x]) for x in range(len(self.header)))

    def __iter__(self):
        return self

class UnicodeDictWriter:
    """
    A CSV writer which will write rows to CSV file "f",
    which is encoded in the given encoding.
    """

    def __init__(self, f, fieldnames, dialect=csv.excel, encoding="utf-8", **kwds):
        # Redirect output to a queue
        self.fieldnames = fieldnames
        self.queue = cStringIO.StringIO()
        self.writer = csv.writer(self.queue, dialect=dialect, **kwds)
        self.stream = f
        self.encoder = codecs.getincrementalencoder(encoding)()
        
    def writeheader(self):
        self.writer.writerow(self.fieldnames)

    def writerow(self, row):
        self.writer.writerow([row[x].encode("utf-8") for x in self.fieldnames])
        # Fetch UTF-8 output from the queue ...
        data = self.queue.getvalue()
        data = data.decode("utf-8")
        # ... and reencode it into the target encoding
        data = self.encoder.encode(data)
        # write to the target stream
        self.stream.write(data)
        # empty queue
        self.queue.truncate(0)

    def writerows(self, rows):
        for row in rows:
            self.writerow(row)


if __name__ == '__main__':
    args = sys.argv
    if len(args) > 1:
        # Make sure your file header is: id,name,age
        filename = sys.argv[1]
    else:
        filename = 'data.csv'
        data = 'id,name,age\n0,aaron,34\n1,john\u00A9,50'.encode('utf-8')
        f = codecs.open(filename, encoding='utf-8', mode='w+')
        f.write(data)
        f.close()
    r = UnicodeDictReader(open(filename, 'r'), skipinitialspace=True)
    w = UnicodeDictWriter(open(filename.replace('.csv', '.out.csv'), 'w'), ['id', 'name', 'age'])
    w.writeheader()
    for row in r:
        print row
        w.writerow(row)