CODEWITHSUNDEEP
pythontimewhile-loopnested
Robert L. Caputo
Robert L. Caputo

Reputation: 1

Python 3: Nested while loops based time

I am trying to run two while loops based on an input condition. In this example, that is taken out and replaced by a 1 == 0 so that 0 can be changed back and forth for testing. Once selected, each while loop should run for 10 seconds and then the input condition checked (replaced by 1 == 0) again.

The problem appears to be in the time comparison, since it never evaluates correctly. What am I missing?

#!/usr/bin/env python3
import time 
import os
import bellmod
while True:
    starttime = time.time()
    print("Start time   " + str(starttime)) #Time check
    elapsedtime = 0 #Reset elasped time to 0 for each loop iteration.
    if 1 == 0: #Change this to run either loop. See if remote or local has precidence. 
        while(elapsedtime < 10):
            print("Inside remote while  " + time.strftime("%H:%M:%S")) #Time check
        elapsedtime = time.time() - starttime #Calculate elasped time.
    else:
        elapsedtime = 0
        while(elapsedtime < 10):
            print("inside bottom of local while  " + str(int(time.time() - starttime))) #Time check
        elapsedtime = time.time() - starttime #Calculate elasped time.

Upvotes: 0

Views: 480

Answers (2)

Martijn Pieters
Martijn Pieters

Reputation: 1121356

Your inner while loops are endless, because elapsedtime is never updated:

while(elapsedtime < 10):
    print("inside bottom of local while  " + str(int(time.time() - starttime))) #Time check
elapsedtime = time.time() - starttime #Calculate elasped time.

elapsedtime is updated after the while loop ends, but that is never reached.

You need to fix your indentation so elapsedtime is calculated each loop iteration:

while(elapsedtime < 10):
    print("inside bottom of local while  " + str(int(time.time() - starttime))) #Time check
    elapsedtime = time.time() - starttime #Calculate elasped time.

Note that while is not a function. Using (...) groups the test expression, but is not needed or normally used. If you pass in values as separate arguments to print(), that takes care of including a separator and conversion to string for you:

while elapsedtime < 10:
    print("inside bottom of local while", int(time.time() - starttime))
    elapsedtime = time.time() - starttime

If you don't need to use elapsedtime in the loop, just inline the calculation:

while time.time() - starttime < 10:
    print("inside bottom of local while", int(time.time() - starttime))

Upvotes: 2

Prune
Prune

Reputation: 77837

You don't change elapsedtime inside the loop ... it's stuck at 0. Indent the last line:

if 1 == 0: #Change this to run either loop. See if remote or local has precidence. 
    while(elapsedtime < 10):
        print("Inside remote while  " + time.strftime("%H:%M:%S")) #Time check
        elapsedtime = time.time() - starttime #Calculate elasped time.
else:
    elapsedtime = 0
    while(elapsedtime < 10):
        print("inside bottom of local while  " + str(int(time.time() - starttime))) #Time check
        elapsedtime = time.time() - starttime #Calculate elasped time.

Upvotes: 1

Related Questions