How can I compare a date and a datetime in Python?

Use the .date() method to convert a datetime to a date:

if item_date.date() > from_date:

Alternatively, you could use datetime.today() instead of date.today(). You could use

from_date = from_date.replace(hour=0, minute=0, second=0, microsecond=0)

to eliminate the time part afterwards.

I am trying to compare date which are in string format like '20110930'

benchMark = datetime.datetime.strptime('20110701', "%Y%m%d") 

actualDate = datetime.datetime.strptime('20110930', "%Y%m%d")

if actualDate.date() < benchMark.date():
    print True

Here is another take which preserves information in case both the inputs are datetimes and not dates, "stolen" from a comment at can't compare datetime.datetime to datetime.date ... convert the date to a datetime using this construct:

datetime.datetime(d.year, d.month, d.day)

Suggestion:

from datetime import datetime

def ensure_datetime(d):
    """
    Takes a date or a datetime as input, outputs a datetime
    """
    if isinstance(d, datetime):
        return d
    return datetime.datetime(d.year, d.month, d.day)

def datetime_cmp(d1, d2):
    """
    Compares two timestamps.  Tolerates dates.
    """
    return cmp(ensure_datetime(d1), ensure_datetime(d2))