from datetime import datetime
now = datetime.now()
def suffix(day):
  suffix = ""
  if 4 <= day <= 20 or 24 <= day <= 30:
    suffix = "th"
  else:
    suffix = ["st", "nd", "rd"][day % 10 - 1]
  return suffix
my_date = now.strftime("%b %d" + suffix(now.day))
print(my_date)

Jan 15th