Parsing time string in Python

问题

I have a date time string that I don\'t know how to parse it in Python.

The string is like this:

Tue May 08 15:14:45 +0800 2012

I tried

datetime.strptime(\"Tue May 08 15:14:45 +0800 2012\",\"%a %b %d %H:%M:%S %z %Y\")

but Python raises

\'z\' is a bad directive in format \'%a %b %d %H:%M:%S %z %Y\'

According to Python doc:

%z UTC offset in the form +HHMM or -HHMM (empty string if the the object is naive).

What is the right format to parse this time string?

回答1:

datetime.datetime.strptime has problems with timezone parsing. Have a look at the dateutil package:

>>> from dateutil import parser
>>> parser.parse("Tue May 08 15:14:45 +0800 2012")
datetime.datetime(2012, 5, 8, 15, 14, 45, tzinfo=tzoffset(None, 28800))

回答2:

Your best bet is to have a look at strptime()

Something along the lines of

>>> from datetime import datetime
>>> date_str = 'Tue May 08 15:14:45 +0800 2012'
>>> date = datetime.strptime(date_str, '%a %B %d %H:%M:%S +0800 %Y')
>>> date
datetime.datetime(2012, 5, 8, 15, 14, 45)

Im not sure how to do the +0800 timezone unfortunately, maybe someone else can help out with that.

The formatting strings can be found at http://docs.python.org/library/time.html#time.strftime and are the same for formatting the string for printing.

Hope that helps

Mark

PS, Your best bet for timezones in installing pytz from pypi. ( http://pytz.sourceforge.net/ ) in fact I think pytz has a great datetime parsing method if i remember correctly. The standard lib is a little thin on the ground with timezone functionality.

回答3:

It has discussed many times in SO. In short, "%z" is not supported because platform not support it. My solution is a new one, just skip the time zone.:

    datetime.datetime.strptime(re.sub(r"[+-]([0-9])+", "", "Tue May 08 15:14:45 +0800 2012"),"%a %b %d %H:%M:%S %Y")

回答4:

Here's a stdlib solution that supports a variable utc offset in the input time string:

>>> from email.utils import parsedate_tz, mktime_tz
>>> from datetime import datetime, timedelta
>>> timestamp = mktime_tz(parsedate_tz('Tue May 08 15:14:45 +0800 2012'))
>>> utc_time = datetime(1970, 1, 1) + timedelta(seconds=timestamp)
>>> utc_time
datetime.datetime(2012, 5, 8, 7, 14, 45)

回答5:

In [117]: datetime.datetime.strptime?
Type:           builtin_function_or_method
Base Class:     <type 'builtin_function_or_method'>
String Form:    <built-in method strptime of type object at 0x9a2520>
Namespace:      Interactive
Docstring:
    string, format -> new datetime parsed from a string (like time.strptime()).

来源：https://stackoverflow.com/questions/10494312/parsing-time-string-in-python