How to find the duration between two 'true' values in a loop

Question

I want to find out the charging duration between when the loop finds its first value of '1' and the last value of '1' it detects. I figured out how to find out the duration between 2 timings, but i am unsure of where i can put the 'timestamp' variable.

Here is my current code

from datetime import datetime

#Duration loop
date_format_str = '%H:%M:%S %p'
foundEnd = False

for i in range(len(dfDur01Mar22)):
    #only display bus 'SG3079S'
    if dfDur01Mar22.iloc[i,1] == 'SG3079S':
        #print 'end' when first '0' appears
        if not foundEnd and dfDur01Mar22.iloc[i,2] == 0:
            print('end')
            foundEnd = True
            #prints the first time its 0
            timestamp = dfDur01Mar22.DateTime[i]
            #print(timestamp + " first")
        #if charging type is 1
        elif dfDur01Mar22.iloc[i,2] == 1:
            print(dfDur01Mar22.iloc[i,0],dfDur01Mar22.iloc[i,1],dfDur01Mar22.iloc[i,2])
            foundEnd = False
            timestamp_2 = dfDur01Mar22.DateTime[i]
            #print(timestamp_2 + "last")
            #Duration between the first '1' and the last '1' detected
            given_time = datetime.strptime(timestamp, date_format_str)
            given_time2 = datetime.strptime(timestamp_2, date_format_str)
    
            total = given_time2 - given_time
            #print(total)

and here is the values that i need to find the duration from

Answer 1

You need 2 variables like start_time, end_time. after your loop you can calculate this duration.

So new concept of your code is like below. FOUND_1_SITUATION is your '1' condition in your loop.

from datetime import datetime

#Duration loop
date_format_str = '%H:%M:%S %p'
foundEnd = False
start_time = False
end_time = False

for i in range(len(dfDur01Mar22)):
    if FOUND_1_SITUATION and not start_time:
       start_time = dfDur01Mar22.DateTime[i]
    else :
       end_time = dfDur01Mar22.DateTime[i]
duration_between_start_end = end_time - start_time

It means whenever your loop is on '1' condition start_time will be initialized once. in other conditions end_time will be updated till end of loop.

After all, you can put duration_between_start_end calculation below your loop.