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Wes McKinney commented on ARROW-1957: ------------------------------------- [~tpboudreau] I assume this is on your critical path > [Python] Write nanosecond timestamps using new NANO LogicalType Parquet unit > ---------------------------------------------------------------------------- > > Key: ARROW-1957 > URL: https://issues.apache.org/jira/browse/ARROW-1957 > Project: Apache Arrow > Issue Type: Improvement > Components: Python > Affects Versions: 0.8.0 > Environment: Python 3.6.4. Mac OSX and CentOS Linux release > 7.3.1611. Pandas 0.21.1 . > Reporter: Jordan Samuels > Assignee: TP Boudreau > Priority: Minor > Labels: parquet > Fix For: 0.14.0 > > > The following code > {code} > import pyarrow as pa > import pyarrow.parquet as pq > import pandas as pd > n=3 > df = pd.DataFrame({'x': range(n)}, index=pd.DatetimeIndex(start='2017-01-01', > freq='1n', periods=n)) > pq.write_table(pa.Table.from_pandas(df), '/tmp/t.parquet'){code} > results in: > {{ArrowInvalid: Casting from timestamp[ns] to timestamp[us] would lose data: > 1483228800000000001}} > The desired effect is that we can save nanosecond resolution without losing > precision (e.g. conversion to ms). Note that if {{freq='1u'}} is used, the > code runs properly. -- This message was sent by Atlassian JIRA (v7.6.3#76005)