Copy from generator

copy_from_generator.py

import psycopg2
import io
import csv
import itertools

class Readable(object):

    def __init__(self, iterator):

        self.output = io.StringIO()
        self.writer = csv.writer(self.output)
        self.iterator = iterator

    def read(self, size):

        self.writer.writerows(itertools.islice(self.iterator, size))

        chunk = self.output.getvalue()
        self.output.seek(0)
        self.output.truncate(0)

        return chunk

con = pyscopg2.connect(...)

with con.cursor() as c:
    c.copy_expert('COPY your_table FROM STDIN WITH CSV',
                  Readable(range(10000000000))