string-representation for Timestamp does not show nanoseconds if present · Issue #5912 · pandas-dev/pandas (original) (raw)
See:
In [27]: str(pd.Timestamp(200))
Out[27]: '1970-01-01 00:00:00'
In [28]: repr(pd.Timestamp(200))
Out[28]: "Timestamp('1970-01-01 00:00:00.000000200', tz=None)"
whereas microseconds work fine:
In [30]: str(pd.Timestamp(2000))
Out[30]: '1970-01-01 00:00:00.000002'