Psycopg2cffi does not obfuscate passwords in connection dsn

[avanov]

Hi!

It seems that there is a small difference in a way how psycopg2cffi and psycopg2 print connection DSNs. The former does not obfuscate passwords, and the latter does (http://initd.org/psycopg/docs/connection.html#connection.dsn).

pg_params = {
    'database': 'solo',
    'user': 'solo',
    'password': 'solo',
    'host': 'localhost',
    'port': 5432
}

conn = psycopg2.connect(**pg_params)

# Result for psycopg2
# "user=solo password=xxx dbname=solo host=localhost port=5432"

# Result for psycopg2cffi
# "dbname=solo user=solo password=solo host=localhost port=5432"

print(conn.dsn)

It is not a big issue by itself, yet it complicates testing of projects that might benefit from being able to supportpsycopg2cffi as a drop-in replacement for psycopg2, for instance, aiopg2 (I'm currently working on this support in aio-libs/aiopg#361).

Here's how psycopg2 obfuscates passwords:

• https://github.com/psycopg/psycopg2/blob/a7e3f46431a85d9d0fd2f1a1a1908867bcc60881/psycopg/connection_type.c#L1252

• https://github.com/psycopg/psycopg2/blob/a7e3f46431a85d9d0fd2f1a1a1908867bcc60881/psycopg/connection_type.c#L1342

P.S. It would be great if we could preserve the order of connection attributes as well