％m 匹配的月份用两位十进制表示（在 [01，12] 中）。将％b 用作缩写的月份名称，或将％B 用作完整的月份名称：

%m matches months represent as a two-digit decimal (in [01, 12]). Use %b for abbreviated month names, or %B for full month names instead:

fmt = '%a %d %b %Y %I:%M %p %Z'

可以找到显示日期格式指令及其含义的表此处。

A table showing the date format directives and their meanings can be found here.

如果您在使用％Z 解析 PDT 时遇到问题：

If you're having trouble parsing PDT using %Z:

每个 time.strptime文档：

对％Z指令的支持基于
tzname中包含的值以及daylight是否为true。因此，它是特定于
的平台，除了可以识别始终为
的UTC和GMT（并被视为非夏时制时区）。

Support for the %Z directive is based on the values contained in tzname and whether daylight is true. Because of this, it is platform-specific except for recognizing UTC and GMT which are always known (and are considered to be non-daylight savings timezones).

因此，如果在不使用PDT的情况下分析日期字符串的工作原理：

So, if parsing the date string without PDT works:

In [73]: datetime.strptime('Sun 11 May 2014 05:00 PM', '%a %d %b %Y %I:%M %p')
Out[73]: datetime.datetime(2014, 5, 11, 17, 0)

但

datetime.strptime('Sun 11 May 2014 05:00 PM PDT', '%a %d %b %Y %I:%M %p %Z')

引发ValueError，那么您可能需要去除时区名称（它们是总的来说，还是模棱两可的）：

raises a ValueError, then you may need strip off the timezone name (they are, in general, ambiguous anyway):

In [10]: datestring = 'Sun 11 May 2014 05:00 PM PDT'

In [11]: datestring, _ = datestring.rsplit(' ', 1)

In [12]: datestring
Out[12]: 'Sun 11 May 2014 05:00 PM'

In [13]: datetime.strptime(datestring, '%a %d %b %Y %I:%M %p')
Out[13]: datetime.datetime(2014, 5, 11, 17, 0)

或使用 dateutil ：

In [1]: import dateutil.parser as parser

In [2]: parser.parse('Sun 11 May 2014 05:00 PM PDT')
Out[2]: datetime.datetime(2014, 5, 11, 17, 0)