Test code

import numpy as np
import time

def timeWrap(func):
    def wrapper(*args, **kwargs):
        t0 = time.time()
        result = func(*args, **kwargs)
        print "It took:", time.time() - t0, "seconds"
        return result
    return wrapper

@timeWrap
def xstr():
    for i in range(10000):
        s = ''
        for j in range(10):
            s += str(j)

@timeWrap
def xlist():
    for i in range(10000):
        s = [0,0,0,0,0,0,0,0,0,0]
        for j in range(10):
            s[j] = j

@timeWrap
def xarray():
    for i in range(10000):
        s = np.ndarray((10,))
        for j in range(10):
            s[j] = j

@timeWrap
def xdict():
    for i in range(10000):
        s = {}
        for j in range(10):
            s[j] = j


print 'str',
xstr()
print 'list',
xlist()
print 'array',
xarray()
print 'dict',
xdict()