The other alternate to avoid the “all or none” leading zero aspect above is to place a minus in front of the field type:
mydatetime.strftime('%-m/%d/%Y %-I:%M%p')
Then this: ‘4/10/2015 03:00AM’
Becomes: ‘4/10/2015 3:00AM’
You can optionally place a minus in front of the day if desired.
Edit: The minus feature derives from the GNU C library (“glibc”) as mentioned in the Linux strftime manpage under “Glibc notes”