2

我的文本文件中的一行：

RCF585 medium Joseph -you entered the parking lot at 3:30 and left at 4:30-

我想要做的是通过车牌号识别汽车，然后知道它是“中型”（它的大小），因此它的总成本是（停车费 * 1.25（税））同时总small is (停车费 * 1.00) 和 big (停车费 * 1.50)。

停车费（每半小时 20 美元）当然取决于汽车停了多长时间，所以我的第二个问题是如何通过阅读相关汽车的线路来读取和识别汽车的停放量。这是我到目前为止成功写的内容：

f=open(file, "r")

which_car= input("Please write your license number: ")

for line in f:

if line.startswith(which_car):        #identifying which car we want to deal with
4

2 回答 2

3

您可以使用re.findall()提取时间，datetime.datetime.strptime()并将提取的字符串转换为日期时间数据：

import re
from datetime import datetime

which_car = input("Please write your license number: ")
file = "text.txt"

with open(file, "r") as f:
    for line in f:
        if line.startswith(which_car):
            time1, time2 = re.findall("\d+:\d+", line)

def string_to_time(string):
    return datetime.strptime(string , '%H:%M')

print(string_to_time(time2) - string_to_time(time1))

测试运行：

Please write your license number: RCF585

输出：

1:00:00

解释：

模式\d+:\d+仅表示冒号两侧的数字，格式%H:%M表示冒号两侧的小时值和分钟值。

open注意：使用运算符将​​调用分配给变量是一种不好的做法=。相反，请使用该with语句。

于 2021-01-06T16:47:50.407 回答
1

我会使用正则表达式来查找文本中的时间，

import re

regex = re.compile(r'(\d{1,2}:\d\d)')
times = regex.findall(line)

并使用datetime和dateutil.relativedelta查找停车时间，

from datetime import datetime
from dateutil.relativedelta import relativedelta

parking_time = relativedelta(datetime.strptime(times[0] , '%H:%M'), datetime.strptime(times[1] , '%H:%M'))
minutes = abs((parking_time.hours * 60) + parking_time.minutes)

因此，所有这些将是：

import re
from datetime import datetime
from dateutil.relativedelta import relativedelta

which_car = input("Please write your license number: ")

with open(file, 'r') as f:
    
    for line in f:

        if line.startswith(which_car):

            size = line.split(' ')[1]

            regex = re.compile(r'(\d{1,2}:\d\d)')
            times = regex.findall(line)
             
            # Update - Ex. 3:27 -> 3:30, 3:35 -> 3:30
            for i in range(len(times)):

                minute = int(times[i].split(':')[1])

                if minute - ((minute // 15) * 15) < 7.5:
                    minute = (minute // 15) * 15
                else:
                    minute = (minute // 15 + 1) * 15

                times[i] = times[i].split(':')[0] + ':' + str(minute)

            parking_time = relativedelta(datetime.strptime(times[0] , '%H:%M'), datetime.strptime(times[1] , '%H:%M'))

            minutes = abs((parking_time.hours * 60) + parking_time.minutes)

            parking_cost = (minutes // 30) * 20
            total_cost = parking_cost   # Default size is small

            if size == 'big':
                total_cost = parking_cost * 1.5
            elif size == 'medium':
                total_cost = parking_cost * 1.25

我建议在处理文件时使用with，因为您不必再​​担心手动关闭文件。

于 2021-01-06T17:22:36.293 回答