I am having trouble getting this code to work? This code is suppoed to find out how long it took for-CodePudding

When I try to run this code I am supposed to get values for the time time it took the program to located[42] but I keep getting an erroe

import random
import time

ranges = [1000, 10000, 100000, 1000000]

dict_times = []
index_times = []
sort_times = []

for i in ranges:

    L = random.sample(range(i), i)
    d = dict(zip(L,L))

    #time for dict ------

    #start the time here
    start = time.time()

    v = d[42]

    #end the time here
    end = time.time()

    dict_times.append(end-start)

    #time for index ------

    #start the time here
    start = time.time()

    ind = L.index(42)

    #end the time here
    end = time.time()

    index_times.append(end-start)

    #time for sort -----

    #start the time here
    start = time.time()

    L = sorted(L)

    #end the time here
    end = time.time()

    sort_times.append(end-start)

print('Times for dictionary lookup:', dict_times, end="\n\n")

print('Times for list lookup:', index_times)
index_ratios = [round(index_times[i]/index_times[i-1], 2) for i in range(1, len(index_times))]
print('List lookup Ratios:', index_ratios, end="\n\n")


print('Times for list sort:', sort_times)
sort_ratios = [round(sort_times[i]/sort_times[i-1], 2) for i in range(1, len(sort_times))]
print('List sort Ratios:', sort_ratios, end="\n\n")

list_sort_over_index = [round(sort_times[i]/index_times[i], 2) for i in range(len(sort_times))]
print('List sort over list lookup:', list_sort_over_index, end="\n\n")

The error I get is: line 57, in index_ratios = [round(index_times[i]/index_times[i-1], 2) for i in range(1, len(index_times) The full error I get is:

runfile('C:/Users/sanil/OneDrive/Desktop/Business App Developement/hw9/turnin/hw09.py.py', wdir='C:/Users/sanil/OneDrive/Desktop/Business App Developement/hw9/turnin', current_namespace=True) Times for dictionary lookup: [0.0, 0.0, 0.0, 0.0]

Times for list lookup: [0.0, 0.0, 0.0, 0.03130626678466797] Traceback (most recent call last):

File "C:\Users\sanil\OneDrive\Desktop\Business App Developement\hw9\turnin\hw09.py.py", line 57, in index_ratios = [round(index_times[i]/index_times[i-1], 2) for i in range(1, len(index_times))]

ZeroDivisionError: float division by zero I am running this code in sypder, am I missing any plug ins in the application, no matter how many times I run the code I am getting the same error

CodePudding user response：

Try using time.perf_counter() by replacing all instances of time.time() in your code with time.perf_counter().

From the time.time() documentation,

[n]ote that even though the time is always returned as a floating point number, not all systems provide time with a better precision than 1 second.

That probably explains why you get 0s as you are subtracting low precision times over very fast operations.