[Sqlalchemy-tickets] Issue #3692: Python3 attempting to query db with string gives "TypeError: string argument without an encoding" (zzzeek/sqlalchemy)

[Gregory R. <iss...@bi...>]

New issue 3692: Python3 attempting to query db with string gives "TypeError: string argument without an encoding"
https://bitbucket.org/zzzeek/sqlalchemy/issues/3692/python3-attempting-to-query-db-with-string

Gregory Rehm:

My code is pretty straightforward: I'm looking for an entry with an email address.

    committed_message = Table.query.filter(
        Table.email_to == email_to
    ).order_by(Table.created_at.desc()).first()

But I get this in response.

    File "/Users/greg/workspace/python/meg-server/venv/lib/python3.5/site-packages/sqlalchemy/orm/query.py", line 2634, in first
    ret = list(self[0:1])
    File "/Users/greg/workspace/python/meg-server/venv/lib/python3.5/site-packages/sqlalchemy/orm/query.py", line 2457, in __getitem__
    return list(res)
    File "/Users/greg/workspace/python/meg-server/venv/lib/python3.5/site-packages/sqlalchemy/orm/loading.py", line 86, in instances
    util.raise_from_cause(err)
    File "/Users/greg/workspace/python/meg-server/venv/lib/python3.5/site-packages/sqlalchemy/util/compat.py", line 200, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb, cause=cause)
    File "/Users/greg/workspace/python/meg-server/venv/lib/python3.5/site-packages/sqlalchemy/util/compat.py", line 184, in reraise
    raise value
    File "/Users/greg/workspace/python/meg-server/venv/lib/python3.5/site-packages/sqlalchemy/orm/loading.py", line 71, in instances
    rows = [proc(row) for row in fetch]
    File "/Users/greg/workspace/python/meg-server/venv/lib/python3.5/site-packages/sqlalchemy/orm/loading.py", line 71, in <listcomp>
    rows = [proc(row) for row in fetch]
    File "/Users/greg/workspace/python/meg-server/venv/lib/python3.5/site-packages/sqlalchemy/orm/loading.py", line 457, in _instance
    unloaded, populators)
    File "/Users/greg/workspace/python/meg-server/venv/lib/python3.5/site-   packages/sqlalchemy/orm/loading.py", line 520, in _populate_partial
    dict_[key] = getter(row)
    File "/Users/greg/workspace/python/meg-server/venv/lib/python3.5/site-packages/sqlalchemy/sql/sqltypes.py", line 859, in process
    value = bytes(value)
    TypeError: string argument without an encoding

It seems like the problem here is a generic one; when I try to feed bytes() a string argument in Python3 it wants an encoding like utf8

So this would fail

   bytes("foo")

While this is ok

   bytes("foo", "utf8")