utils.py

#handy util functions
import math

class Bunch:
    def __init__(self, **kwds):
        self.__dict__.update(kwds)
    
    def __repr__(self):
        args = ['%s=%s' % (k, repr(v)) for (k,v) in vars(self).items()]
        return 'Bunch(%s)' % ', '.join(args)


def mean(lst):
    """mean(lst) -> the arithmetic mean of the values in LST"""
    return sum(lst) / float(len(lst))

def variance(lst):
    """variance(lst) -> variance of values in LST"""
    mu = mean(lst)
    return sum((v - mu) ** 2 for v in lst) / float(len(lst))

def stddev(lst):
    """stddev(lst) -> standard deviation of values in LST"""
    return math.sqrt(variance(lst))

def init_completion():
    try:
        import readline
    except ImportError:
        print "Module readline not available."
    else:
        import rlcompleter
        readline.parse_and_bind("tab: complete")

def repl(local=None):
    """start a repl.  use: repl(local=locals()) to get current env.
       if IPython is available, use:
           import IPython; IPython.embed()"""
    import code
    init_completion() 
    code.interact(local=local)