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def chunked_list(lst, size):
    """
    Iterates over chunks of a list
    """
    for i in xrange(0, len(lst), size):
       yield lst[i:i+size]

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def expand_with_args(*parameters, **kwargs):
    """
    For each set of args, makes a copy of the function with the args bound, and
    with the repr of the args appended to the name. Assigns that to the calling
    frame's locals. Adapted from http://stackoverflow.com/a/4455312/278488.
    Meant for use with unit tests, to create multiple tests from a parameterized
    method.
    """
    def tuplify(x):
        if not isinstance(x, tuple):

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from subprocess import Popen, PIPE, CalledProcessError


def check_teed_output(*popenargs, **kwargs):
    """
    Like check_output, but also tees the output to a file object specified
    by the stdout kwarg. Passing in stdout=sys.stdout allows you to run the
    process with normal output (like check_call()) but also get the output
    as the return value (like check_output()).
    """

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def utc_to_local(dt):
    """
    Converts a naive datetime from UTC to local time, returning a new naive
    datetime.
    """
    return datetime.fromtimestamp(calendar.timegm(dt.utctimetuple()))

def local_to_utc(dt):
    """
    Converts a naive datetime from local to UTC time, returning a new naive

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# Required because datetime.date is a builtin type that can't be modified
class MockDate(date):
    "A wrapper for date that can be mocked for testing."

    def __new__(cls, *args, **kwargs):
        return date.__new__(date, *args, **kwargs)

# Required because datetime.datetime is a builtin type that can't be modified
class MockDateTime(datetime):
    "A wrapper for datetime that can be mocked for testing."

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def copy_mtime(src, dest):
    # Don't use os.utime() or shutil.copystat() -- these both truncate the
    # time due to python's float not having as much resolution as the
    # filesystem -- see http://ciaranm.wordpress.com/2009/11/15/this-week-in-python-stupidity-os-stat-os-utime-and-sub-second-timestamps/
    #
    # If the truncation during reading (from os.stat()) was the same as the
    # truncation during writing, the problem would be transparent here (but
    # would still affect other non-truncating code), however python takes the
    # problem to a new level and truncates an extra decimal place during write.
    # Either way, it's best to avoid the write truncation altogether.