Pyarrow engine incorretly serialize timestamp with Z.

[thomasfrederikhoeck]

Environment

Delta-rs version: main

Binding: python

Environment:

• Cloud provider:
• OS: windows
• Other:

---

Bug

What happened:
Pyarrow serialize timestamp with Z in the end incorrectly which is in contrast to timestampNtz which is correct without Z.

What you expected to happen:
Both without Z
How to reproduce it:

import pyarrow as pa
import pytz

tz = "UTC"

def get_data(with_tz):
    tzinfo = pytz.timezone(tz) if  with_tz else None
    dates = pd.date_range(
        datetime(2021,1,1,3,4,6,3, tzinfo=tzinfo),
        datetime(2021,1,3,3,4,6, tzinfo=tzinfo)
        )
    return pd.DataFrame({"time":dates, "a":[i for i in range(len(dates))]})

schema = pa.schema(
        [
            ("time", pa.timestamp("us")),
            ("a", pa.int64()),
        ]
    )
dt = DeltaTable.create(
        "mytable_timestampNtz", schema=schema, partition_by=["time"]
    )

write_deltalake("mytable_timestampNtz",get_data(with_tz=False), partition_by="time", mode="append")
print(dt.schema())
schema = pa.schema(
        [
            ("time", pa.timestamp("us",tz)),
            ("a", pa.int64()),
        ]
    )
dt = DeltaTable.create(
        "mytable_timestamp", schema=schema, partition_by=["time"]
    )

write_deltalake("mytable_timestamp",get_data(with_tz=True), partition_by="time", mode="append")
print(dt.schema())

>Schema([Field(time, PrimitiveType("timestampNtz"), nullable=True), Field(a, PrimitiveType("long"), nullable=True)])
>Schema([Field(time, PrimitiveType("timestamp"), nullable=True), Field(a, PrimitiveType("long"), nullable=True)])

More details: