获取 JSON 列表中的第一个和最后一个元素并查找时差

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，我完成的工作是获取驱动程序日志的所有状态更改以及与这些日志关联的事件。我现在只想每天显示每个司机的第一个和最后一个事件，并跳过每个司机之间的所有事件，但似乎不明白该怎么做。

#!/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，我试图实现的是，一旦我为每个驱动程序提供了第一个和最后一个事件，我想找到这两个事件之间的时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，您可以保存有关列表中事件的所有必要信息，包括 datetime 对象，其中列表中的每个条目都是一个元组，其中包含有关事件的所有信息。然后，您可以根据日期时间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。两个日期时间对象之间的差异将为您提供时间增量，可以很容易地转换为秒。

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