overallocation stuff

over.py

from random import shuffle
from time import time

def make_lists(L):
    L1, L2, L3 = [], [], []
    for e in L:
        L1.append(e)
        L2.append(e)
        L3.append(e)
    return L1, L2, L3

def make_many(L, n):
    for _ in range(n):
        ret = make_lists(L)
    return ret

N_APPENDS = 100_000_000
def trial(n_els):
    n_loops = N_APPENDS // n_els

    L = list(range(n_els))
    shuffle(L)
    start = time()
    make_many(L, n_loops)
    delta = time() - start
    per_app = (delta / N_APPENDS) * 1e9
    print("%12.1f %12d %12.0f" % (delta, n_els, per_app))

print("%-12s %-12s %-12s" % ("tot (s)", "n_els", "append (ns)"))
sizes = sum([[e*10**i for e in [2, 5, 10]] for i in range(5)], [])
for n_els in sizes:
    trial(n_els)