#3520 Stream map expressions: datetime module not accessible for attribute access (in functions dict, not names) Issue created by abrostoff Bug Description The

datetime

module is added to the simpleeval

functions

dict in

CustomStreamMap.functions

(mapper.py line 322), but it is not added to the

names

dict in

_eval()

. This means expressions like

datetime.datetime.utcnow().isoformat()

fail with:

simpleeval.AttributeDoesNotExist: Attribute 'datetime' does not exist in expression 'datetime.datetime.utcnow().isoformat()'

In simpleeval, entries in

functions

are only invocable as

name(args)

— they do not support attribute/dot access. Attribute access requires the entry to be in the

names

dict. Expected Behavior As documented in the Inline Stream Maps docs, the

datetime

module should be usable in expressions with attribute access: stream_maps: mystream: loaded_at: "datetime.datetime.utcnow().isoformat()" create_year: "int(datetime.date.fromisoformat(create_date).year)" The SDK's own type detection logic in

_get_type()

also explicitly expects these patterns to work: # mapper.py lines 419-425 if expr.startswith(("datetime.date.", "datetime.date(")) or expr.endswith(".date()"): return th.DateType() if expr.startswith(("datetime.datetime.", "datetime.datetime(")): return th.DateTimeType() Suggested Fix Add

datetime

to the

names

dict in

_eval()

, alongside

record

,

config

, etc.: names["datetime"] = datetime (And similarly for

json

if it has the same issue.) Environment • singer-sdk version: 0.53.5 (latest) • Python version: 3.12 meltano/sdk