performance - Is it faster to add a key to a dictionary or append a value to a list in Python? -


i have application need build list or dictionary , speed important. declare list of zeros of appropriate length , assign values 1 @ time need able check length , have still meaningful.

would faster add key value pair dictionary or append value list? length of lists , dictionary small (less 100) isn't true , in worst case larger.

i have variable keep track of in list if both of these operations slow.

best way use time() check execution time.

in following example dict faster.

from time import time  st_time = time() b = dict() in range(1, 10000000):     b[i] =  print (time() - st_time)  st_time = time() = [] in range(1, 10000000):     a.append(i)  print (time() - st_time)  1.45600008965 1.52499985695

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