Python 用指針遍歷列表

Question

I am trying to create a session template of dates for a dataframe in pandas based on the start and end day of the week of my given dataframe. 我有開始和結束日期的縮寫（Mo、Tu、We 等）和開始/結束時間（上午 8:30、下午 5:30 等）。

我想要創建的是一個模板，它給出了開始日的縮寫、跨越的時間和結束日。 例如，我的 dataframe 目前如下所示：

Start Time  End Time    Start/End            Namestart Nameend    Days           Session Template   
Mo 8:30 AM  Th 5:30 PM  Mo 8:30 AM-Th 5:30 PM    Mo      Th       4 Day       4 Day Mo 8:30 AM-Th 5:30 PM
We 8:30 AM  Fr 12:30 PM We 8:30 AM-Fr 12:30 PM   We      Fr       3 Day     3 Day We 8:30 AM-Fr 12:30 PM

當前的 session 模板為我提供了天數、開始時間、結束時間以及它開始/結束的星期幾。 但是，我希望它給出該項目跨越的每一天。 對於上面的示例，它應該產生：

4 Day Mo 8:30 AM-5:30 PM, Tu 8:30 AM-5:30 PM, We 8:30 AM-5:30 PM, Th 8:30 AM-5:30 PM. 
3 Day We 8:30 AM-5:30 PM, Th 8:30 AM-5:30 PM, Fr 8:30 AM-12:30 PM

Answer 1

您可以這樣做：

import pandas as pd
import re
import itertools
pd.set_option('display.max_columns', 100)
pd.set_option('display.width', 1000)

df = pd.read_csv("data.csv")
print(df, "\n")

days = ['Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa', 'Su']

for index, row in df.iterrows():
    # get the start and end days
    start_day = row['Namestart']
    end_day = row['Nameend']
    # get the start end end times
    start_time = re.findall(r'\s(\d+\:\d{2}\s?(?:AM|PM|am|pm))',
                           row['Start Time'])[0]
    end_time = re.findall(r'\s(\d+\:\d{2}\s?(?:AM|PM|am|pm))',
                         row['End Time'])[0]
    # get the indices corresponding to the start and end days
    start_index = days.index(start_day)
    end_index = days.index(end_day)+1
    # count the number of days
    cnt = end_index - start_index
    print(cnt, "days\t", end='')
    # slice the days list from start_index to end_index
    for day in itertools.islice(days, start_index, end_index):
        if (day!=end_day):
            print(day, start_time, "- 5:30 PM\t", end='')
        else:
            print(day, start_time, "-", end_time, end='')
    print() # to start a new line before printing each row

Output：

   Start Time     End Time               Start/End Namestart Nameend   Days              Session Template
0  Mo 8:30 AM   Th 5:30 PM   Mo 8:30 AM-Th 5:30 PM        Mo      Th  4 Day   4 Day Mo 8:30 AM-Th 5:30 PM
1  We 8:30 AM  Fr 12:30 PM  We 8:30 AM-Fr 12:30 PM        We      Fr  3 Day  3 Day We 8:30 AM-Fr 12:30 PM 

4 days  Mo 8:30 AM - 5:30 PM    Tu 8:30 AM - 5:30 PM    We 8:30 AM - 5:30 PM    Th 8:30 AM - 5:30 PM
3 days  We 8:30 AM - 5:30 PM    Th 8:30 AM - 5:30 PM    Fr 8:30 AM - 12:30 PM

注釋應該解釋代碼。 我使用的正則表達式的解釋可以在這個答案中找到 - https://stackoverflow.com/a/49217300/6590393 。

另外，請注意上面的代碼是基於你只在列表中前進的假設。 因此，例如，Sa-Mo 不會產生預期的結果。 如果您需要，我會留給您處理邊界情況。