Timedelta string values cannot be converted with the dtype parameter

[DrGFreeman]

Timedelta string values stored in a table cannot be converted with the dtype parameter of the get_df and to_df functions or using the dataframe astype method. This is due to a known bug in pandas (ref.: pandas-dev/pandas#38509).

As a result, unit tests for the dtype parameter of the get_df and put_df function do not test this conversion. Once the pandas issue is resolved, this conversion can be added to the tests.

As a workaround, the Timedelta columns can be converted using pd.to_timedelta(df.column_name).

[DrGFreeman]

Tests to update:

dynamo-pandas/tests/test_main.py

Line 122 in 72df84b

# "C": "timedelta64[ns]", # Ref. #24

dynamo-pandas/tests/test_main.py

Line 221 in 72df84b

# C="timedelta64[ns]", # Ref. #24

[DrGFreeman]

Docs to update:

• README.md
• docs/overview.rst

• dynamo-pandas/dynamo_pandas/dynamo_pandas.py

  Lines 83 to 101 in 99e09c7

  	.. note:: Due to a
  	`known bug in pandas <https://github.com/pandas-dev/pandas/issues/38509>`_,
  	timedelta strings cannot currently be converted back to timedelta64 type via the
  	``dtype`` parameter. Use the ``pandas.to_timedelta`` function instead:
  	>>> df.play_time = pd.to_timedelta(df.play_time)
  	>>> df.info()
  	<class 'pandas.core.frame.DataFrame'>
  	RangeIndex: 2 entries, 0 to 1
  	Data columns (total 5 columns):
  	# Column Non-Null Count Dtype
  	--- ------ -------------- -----
  	0 bonus_points 1 non-null Int8
  	1 player_id 2 non-null object
  	2 last_play 2 non-null datetime64[ns, UTC]
  	3 rating 2 non-null float64
  	4 play_time 2 non-null timedelta64[ns]
  	dtypes: Int8(1), datetime64[ns, UTC](1), float64(1), object(1), timedelta64[ns](1)
  	memory usage: 196.0+ bytes