Trouble using datetime.strptime()

问题

I have an Excel spreadsheet. I am trying to capture a line from the Excel sheet that contains a date, then parse the date out with datetime.strptime().

Here is the bit of the Excel sheet I'm working with:

and my relevant code:

pattern = re.compile(r'Listing(.+)', re.IGNORECASE)

a = pattern.findall(str(df))
print("a:", a)

new_a = str(a)
datetime_object = datetime.strptime(new_a, '%b %w %Y')
print("date:", datetime_object)

So I capture everything that follows LISTING and produce:

a: [' JUN 11 2013 Unnamed: 1 \\']

Then I try to extract the Jun, 11, and 2013 but I fail with:

ValueError: time data "[' JUN 11 2013 Unnamed: 1 \\\\']" does not match format '%b %w %Y'

I am fairly sure this is a simple fix but being a beginner I can't see how exactly to fix it. Should I alter my RegEx to capture less? Or should I fix the arguments that date.strptime() is taking in?

The arguments seem to be right when looking at the documentation: https://docs.python.org/3.5/library/datetime.html

Thanks for any help.

回答1:

You need to modify the regex you're using to get the date from the Excel file.

pattern = re.compile(r'Listing ([A-Z]+ \d{1,2} \d{4})', re.IGNORECASE)

[A-Z]+ means "one or more capital letters", \d{1,2} means "one or two numbers" and \d{4} means "four numbers".

Furthermore the format of date you're using is incorrect - %w means weekday (numbers from 0 to 6 representing weekdays from Sunday to Saturday), while you should use %d which matches day of the month

So it should look like this in the end: datetime_object = datetime.strptime(new_a, '%b %d %Y')

来源：https://stackoverflow.com/questions/42558338/trouble-using-datetime-strptime

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python

regex

excel

datetime

strptime