如何将字符串中的时间转换为日期时间格式，以便可以获取两列之间的差异

Question

I have a dataframe with two columns with different times in string format, I want to find the difference between the two columns so I use the following code

operational_data_clean['Pick/pack start-time'] = pd.to_datetime(operational_data_clean['Pick/pack start-time'])

operational_data_clean['Flight launched-time'] = pd.to_datetime(operational_data_clean['Flight launched-time'])

operational_data_clean['time_to_launch'] = 0

operational_data_clean['time_to_launch'] = operational_data_clean['Flight launched-time'] - operational_data_clean['Pick/pack start-time']

but this code when I run the first time I get good results but when I run the second time it add todays date on the 'Pick/pack start-time' and 'Flight launched-time' value.

How can I convert this time only to hours without getting the dates that are messing my data.

Answer 1

I am assuming you are running your code with jupyter notebook.

When you execute your code, your variable operational_data_clean['Pick/pack start-time'] becomes pd.to_datetime(operational_data_clean['Pick/pack start-time']) .

So when you execute the block one more time, jupyter remembers your variables and therefore will perform the same function again, essentially doing this: pd.to_datetime(pd.to_datetime(operational_data_clean['Pick/pack start-time'])) .

As for pd.to_datetime() itself, I would advise to look through the pandas docs .