Parsing string to datetime while accounting for AM/PM in pandas

Question

I am trying to parse a string in this format "2018 - 07 - 07 04 - AM" to pandas datetime using strftime format. However, It seems to me the format doesn't recognize the difference between AM and PM.

Here is what I tried:

pd.to_datetime("2018 - 07 - 07 04 - PM", format='%Y - %m - %d %H - %p').timestamp()
Out[4]: 1530936000.0
pd.to_datetime("2018 - 07 - 07 04 - AM", format='%Y - %m - %d %H - %p').timestamp()
Out[5]: 1530936000.0

Notice how the AM and PM are different in the above two strings, yet the same timeStamp is returned.

Pandas version: 0.23.3

Python version: 3.5.4

Answer 1

Since you're parsing a 12-hour time format, you will need %I instead of %H, otherwise the %p specifier has no effect.

pd.to_datetime("2018 - 07 - 07 04 - PM", format='%Y - %m - %d %I - %p')
Timestamp('2018-07-07 16:00:00')

This behaviour is documented in the docs:

When used with the strptime() function, the %p directive only affects the output hour field if the %I directive is used to parse the hour.