strptime

I have three date formats: YYYY-MM-DD , DD.MM.YYYY , DD/MM/YYYY . Is it possible to validate and parse strings such as 2014-05-18 or 18.5.2014 or 18/05/2019 ? Try each format and see if it works: from datetime import datetime def try_parsing_date(text): for fmt in ('%Y-%m-%d', '%d.%m.%Y', '%d/%m/%Y'): try: return datetime.strptime(text, fmt) except ValueError: pass raise ValueError('no valid date format found') >>> import dateutil.parser >>> dateutil.parser.parse(date_string) This should take care of most of the standard date formats in Python 2.7+. If you really have super custom date formats

How do I use strptime or any other functions to parse time stamps with milliseconds in R? time[1] # [1] "2010-01-15 13:55:23.975" strptime(time[1], format="%Y-%m-%d %H:%M:%S.%f") # [1] NA strptime(time[1], format="%Y-%m-%d %H:%M:%S") # [1] "2010-01-15 13:55:23"` Courtesy of the ?strptime help file (with the example changed to your value): z <- strptime("2010-01-15 13:55:23.975", "%Y-%m-%d %H:%M:%OS") z # prints without fractional seconds op <- options(digits.secs=3) z options(op) #reset options You can also use strptime(time[1], "%OSn") where 0 <= n <= 6, without having to set digits.secs . 来源

I have some log files with times in the format HH:MM::SS.nano_seconds (e.g. 01:02:03.123456789). I would like to create a datetime in python so I can neatly do math on the time (e.g. take time differences). strptime works well for microseconds using %f. Do the Python datetime and time modules really not support nanoseconds? Dougal You can see from the source that datetime objects don't support anything more fine than microseconds. As pointed out by Mike Pennington in the comments, this is because actual hardware clocks aren't nearly that precise . Wikipedia says that HPET has frequency "at