获取JSON列表中的第一个和最后一个元素并找到时差

Question

我正在尝试从此端点提取数据：https://developer.keeptruckin.com/reference#get-logs

到目前为止，我已经完成的工作是获取驱动程序日志的所有状态更改以及与之相关的事件。我现在只想显示每个驾驶员每天的第一个事件和最后一个事件，并跳过每个驾驶员之间的所有事件，但是似乎不知道该怎么做。

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import requests
import json
import csv
import math

url='https://api.keeptruckin.com/v1/logs?start_date=2020-01-20&end_date=2020-02-03'
header={'x-api-key':'API_KEY_HERE','x-time-zone':'Pacific Time (US & Canada)'}
r=requests.get(url,headers=header)
result=r.json()
result = json.loads(r.text)
num_pages=math.ceil((result['pagination']['total'])/100)
for page in range (1,num_pages):
    r=requests.get(url,headers=header, params={'page_no': page,'per_page':'100'})
    result=r.json()
    result = json.loads(r.text)
    csvheader=['First Name','Last Name','Date','Time','Type','Location','Vehicle']
    with open('test.csv', 'a+', newline='') as csvfile:
        writer = csv.writer(csvfile, csv.QUOTE_ALL)
        ##writer.writerow(csvheader)
        for log in result['logs']:
            username = log['log']['driver']['username']
            first_name=log['log']['driver']['first_name']
            last_name=log['log']['driver']['last_name']
            for vehicle in log['log']['vehicles']:
                number=vehicle['vehicle']['number']
            for event in log['log']['events']:
                start_time = event['event']['start_time']
                date, time = start_time.split('T')
                time1,time2=time.split('-')
                event_type = event['event']['type']
                location = event['event']['location']
                if not location:
                    location = "N/A"
                if (event_type=="on_duty" or event_type=="driving" or event_type=="off_duty"):
                    writer.writerow((first_name, last_name,date, time1, event_type, location, number))

在此步骤之后，我想要实现的是，一旦我有了每个驱动程序的第一个和最后一个事件，我想找到这两个事件之间的时间差并将其添加到新列中。

Answer 1

您可以使用dateutil.parser解析字符串，它将为您提供datetime对象。然后可以将有关事件的所有必要信息保存在列表中，包括datetime对象，列表中的每个条目都是一个包含有关事件的所有信息的元组。然后，您可以基于datetime对象对列表进行排序。从列表中，您可以取出第一个和最后一个事件。两个datetime对象之间的差异将为您提供timedelta，可以轻松将其转换为秒。

from dateutil.parser import parse
for log in result['logs']:
        username = log['log']['driver']['username']
        first_name=log['log']['driver']['first_name']
        last_name=log['log']['driver']['last_name']
        for vehicle in log['log']['vehicles']:
            number=vehicle['vehicle']['number']
        events = []
        for event in log['log']['events']:
            start_time = parse(event['event']['start_time'])
            end_time = parse(event['event']['end_time'])


            location = event['event']['location']
            # add all data as tuple you want to save for event
            events.append((start_time,end_time, location))
        #sort based on first element of tuple -- start_time
        events.sort(key=lambda x: x[0])      
        first_event = events[0]
        last_event = events[-1]
        #time difference in seconds
        time_diff = (first_event[0]-last_event[0]).seconds # first_event[0] -- start time