Create a program that outputs the times in which the values in another list satisfies a condtion-CodePudding

So for example say I have a list of times (0,1,2,3,4,5) in seconds, and I have another list of speeds at those times (0,0.5,1,1.5,2,2.5) in m/s.

How would I write a program that can tell me which speeds in the second list cross a threshold of 1 m/s and also the times at which those speeds were measured.

the output would look something like :

speeds that cross threshold: [1.5,2,2.5]

times that speed cross threshold: [3,4,5]

so far I've managed to create the first part using this code:

https://i.stack.imgur.com/ii8tF.png

I'm not sure how to get the specific times based on when those speeds are greater than the threshold.

CodePudding user response：

You could pair each time of measure with it's speed and then return a list with only the time values such that their speed is greater than the threshold.

time_list = [0,1,2,3,4,5]
speed_list = [0,0.5,1,1.5,2,2.5]

def find_times(times, speeds, threshold):
    timexspeed = list(zip(times, speeds))
    return [time for time, speed in timexspeed if speed > threshold]

find_times(time_list, speed_list, 1)
>>>[3, 4, 5]

Alternative, as I suggested in comments, you can use a strategy based on iterating through the length of the list instead of it's elements:

for i in range(len(list1)):
    if list1[i] <some_condition>:
        <do_domething_with> list2[i]

CodePudding user response：

You could use pandas

import pandas as pd
df = pd.DataFrame()
df['time'] = (0,1,2,3,4,5)
df['speed'] = (0,0.5,1,1.5,2,2.5)

cutoff = 1
df[df.speed >= cutoff].time