Plotting pandas timedelta

Question

I have a pandas dataframe that has two datetime64 columns and one timedelta64 column that is the difference between the two columns. I'm trying to plot a histogram of the timedelta column to visualize the time differences between the two events.

However, just using df['time_delta'] results in: TypeError: ufunc add cannot use operands with types dtype('<m8[ns]') and dtype('float64')

Trying to convert the timedelta column to : float--> df2 = df1['time_delta'].astype(float) results in: TypeError: cannot astype a timedelta from [timedelta64[ns]] to [float64]

How would one create a histogram of pandas timedelta data?

Answer 1

Here are ways to convert timedeltas, docs are here

In [2]: pd.to_timedelta(np.arange(5),unit='d')+pd.to_timedelta(1,unit='s') Out[2]:  0   0 days, 00:00:01 1   1 days, 00:00:01 2   2 days, 00:00:01 3   3 days, 00:00:01 4   4 days, 00:00:01 dtype: timedelta64[ns] 

Convert to seconds (is an exact conversion)

In [3]: (pd.to_timedelta(np.arange(5),unit='d')+pd.to_timedelta(1,unit='s')).astype('timedelta64[s]') Out[3]:  0         1 1     86401 2    172801 3    259201 4    345601 dtype: float64 

Convert using astype will round to that unit

In [4]: (pd.to_timedelta(np.arange(5),unit='d')+pd.to_timedelta(1,unit='s')).astype('timedelta64[D]') Out[4]:  0    0 1    1 2    2 3    3 4    4 dtype: float64 

Division will give an exact repr

In [5]: (pd.to_timedelta(np.arange(5),unit='d')+pd.to_timedelta(1,unit='s')) / np.timedelta64(1,'D') Out[5]:  0    0.000012 1    1.000012 2    2.000012 3    3.000012 4    4.000012 dtype: float64