python - 在 python 中从 CSV 获取特定时间间隔的数据

Question

我正在从 python 中的 CSV 文件获取特定日期的数据。现在，我想获取特定时间的数据，例如特定日期的 13:30 到 14:30。我的 CSV 文件如下所示:

15   2017/02/07  17:30:45.983
15   2017/02/07  17:30:51.109
16   2017/02/07  17:30:56.008
16   2017/02/07  17:31:01.029

我当前的代码是这样的:

    import csv
    from tkinter import *
    from tkinter.filedialog import askopenfilename
    from tkinter.messagebox import showwarning, showinfo
    import datetime
    import matplotlib.pyplot as plt





    #csv_file = csv.reader(open("C:\Users\Lala Rushan\Downloads\ARIF Drop Monitoring Final\ARIF Drop Monitoring Final\DataLog.csv"))
    from Tools.scripts.treesync import raw_input
    class App(Frame):
        def __init__(self, master):
            Frame.__init__(self, master)


            button1 = Button(self, text="Browse for a file", command=self.askfilename)
            button2 = Button(self, text="Count the file", command=self.takedate)
            button3 = Button(self, text="Exit", command=master.destroy)
            button1.grid()
            button2.grid()
            button3.grid()
            self.userInputFromRaw = Entry(self)
            self.userInputFromRaw.grid()

            self.userInputToRaw = Entry(self)
            self.userInputToRaw.grid()

            self.grid()

        def askfilename(self):
            in_file = askopenfilename()
            if not in_file.endswith(('.CSV')):
                showwarning('Are you trying to annoy me?', 'How about giving me a CSV file, genius?')
            else:
                self.in_file=in_file

        def CsvImport(self,csv_file):


            dist = 0
            for row in csv_file:
                _dist = row[0]
                try:
                    _dist = float(_dist)
                except ValueError:
                    _dist = 0

                dist += _dist
            print ("Urine Volume is: %.2f" % (_dist*0.05))


        def takedate(self):
            from_raw = self.userInputFromRaw.get()
            from_date = datetime.date(*map(int, from_raw.split('/')))
            print ('From date: = ' + str(from_date))
            to_raw = self.userInputToRaw.get()
            to_date = datetime.date(*map(int, to_raw.split('/')))
            in_file = ("H:\DataLog.csv")
            in_file= csv.reader(open(in_file,"r"))

            for line in in_file:
                _dist = line[0]
                try:
                    file_date =  datetime.date(*map(int, line[1].split(' ')[1].split('/')))
                    if from_date <= file_date <= to_date:
                        self.CsvImport(in_file)

                except IndexError:
                    pass






    root = Tk()
    root.title("Urine Measurement")
    root.geometry("500x500")
    app = App(root)
    root.mainloop()

如何获取特定时间和特定日期的数据？

Answer 1

使用pandas及其DataFrame容器，因为这是处理和选择数据的理想格式。请参阅下面的示例:

import pandas as pd
df = pd.read_csv('eg.txt', header=None) # Read in the Data.
df.index = [pd.datetime.strptime(i, '%Y/%m/%d%H:%M:%S.%f') for i in (df[1] + df[2])] # Format the time into the index

这里

>>> df
                          0           1             2    3
2017-02-07 17:30:45.983  15  2017/02/07  17:30:45.983  3.3
2017-02-07 17:30:51.109  15  2017/02/07  17:30:51.109  4.4
2017-02-07 17:30:56.008  16  2017/02/07  17:30:56.008  5.2
2017-02-07 17:31:01.029  16  2017/02/07  17:31:01.029  NaN

您可以选择您想要使用的时间范围:

>>> df[pd.datetime(2017, 2, 7, 17, 30, 50):pd.datetime(2017, 2, 7, 17, 30, 58)] # Slice the wanted time
                          0           1             2    3
2017-02-07 17:30:51.109  15  2017/02/07  17:30:51.109  4.4
2017-02-07 17:30:56.008  16  2017/02/07  17:30:56.008  5.2

其中生成数据的csv是eg.txt，如下所示。

15,2017/02/07,17:30:45.983,3.3
15,2017/02/07,17:30:51.109,4.4
16,2017/02/07,17:30:56.008,5.2
16,2017/02/07,17:31:01.029,NaN

然后您可以根据需要删除、创建、移动列和数据。