如何使用Python解析.txt文件的特定部分？

Question

I have a .txt with data I need to parse to an object that should then be put in a list . The .txt file i huge but here's a sample:

5764;3/13/2015 8:00:00 AM;3/13/2015 1:00:00 PM;
C5CA;1/3/2015 12:30:00 PM;1/3/2015 1:00:00 PM;

It's all in one chunk, separated with semicolons. The sample consists of two objects with id , time_start and time_end

I have created a class that looks like this:

class Employee:

def __init__(self, id, time_start, time_end):
    self.id = id
    self.time_start = time_start
    self.time_end = time_end

The main part looks like this, with opening the file and trying to parse it:

my_array_with_objects = []

my_file = open("test.txt", "r")

for item in my_file:
    temp_employee = Employee()
    temp_employee.id = item_first_semicolon_part
    temp_employee.time_start = item_second_semicolon_part
    temp_employee.time_end = item_third_semicolon_part

    my_array_with_objects.append(temp_employee)

myFile.close()

So, the problem is, I don't know how to access the specific parts of the .txt file, separated by the semicolons. Obviously "item_first_semicolon_part" won't work. But how do I access the first part of the text file so that I do get the id number and nothing else (and then the start and end times)? Is there an elegant way of doing this or simply a matter of using if ; do this if ; do this .

Thanks in advance. I have looked through similar questions, but don't think there was anything that could help me through this.

UPDATE I got a great answer from @Alderven that worked, but I just noticed that the parsed object cuts away a part of the id. I simplified the id for the sake of this question. Full id (with the rest of the data) looks like this:

57646786307395936680161735716561753784;3/13/2015 8:00:00 AM;3/13/2015 1:00:00 PM;C5CAACCED1B9F361761853A7F995A1D4F16C8BCD0A5001A2DF3EC0D7CD539A09AA7DDA1A5278FA07554B0260880882CCBB30B3399C3C0974C587A8233E5788A81DEAD2921123CB12D13CC11318C38B9679D868145315F1BE24333202D12B3787E51D1BBF97BB25482B0EF7E97DE637BAACEDD74E89E2AC52139EE9369F1D64A6 259939411636051033617118653993975778241;1/3/2015 12:30:00 PM;1/3/2015 1:00:00 PM;

The part: C5CAACCED1B9F361761853A7F995A1D4F16C8BCD0A5001A2DF3EC0D7CD539A09AA7DDA1A5278FA07554B0260880882CCBB30B3399C3C0974C587A8233E5788A81DEAD2921123CB12D13CC11318C38B9679D868145315F1BE24333202D12B3787E51D1BBF97BB25482B0EF7E97DE637BAACEDD74E89E2AC52139EE9369F1D64A6

seems to be missing. Perhaps because it is on the same row as the first object. The last part of the id is still there:

259939411636051033617118653993975778241

How do I get the full id?

Answer 1

Actually it is CSV format with ; delimiter. Basically:

import csv

with open('test.txt', newline='\n') as f:
    reader = csv.reader(f, delimiter=';')
    for row in reader:
        print(row)

If you want to parse data to your Employee class, then:

import csv

class Employee:
    def __init__(self, id, timeStart, timeEnd):
        self.id = id
        self.timeStart = timeStart
        self.timeEnd = timeEnd

myArrayWithObjects = []
with open('test.txt', newline='\n') as f:
    reader = csv.reader(f, delimiter=';')
    for row in reader:
        myArrayWithObjects.append(Employee(row[0], row[1], row[2]))

Answer 2

You need to split the line by ; using str.split :

>>> line = "5764;3/13/2015 8:00:00 AM;3/13/2015 1:00:00 PM;"
>>> parts = line.split(";")
>>> parts
['5764', '3/13/2015 8:00:00 AM', '3/13/2015 1:00:00 PM', '']
>>> ID = parts[0]
>>> start = parts[1]
>>> end = parts[2]
>>> ID
'5764'
>>> start
'3/13/2015 8:00:00 AM'
>>> end
'3/13/2015 1:00:00 PM'

You can shorten this by removing the last ; from the line and assigning multiple values at once:

>>> line = "5764;3/13/2015 8:00:00 AM;3/13/2015 1:00:00 PM;"
>>> line = line.strip(";")
>>> ID, start, end = line.split(";")
>>> ID
'5764'
>>> start
'3/13/2015 8:00:00 AM'
>>> end
'3/13/2015 1:00:00 PM'

Answer 3

you can split a row using item.split(';') to get turn it into a list.

you could also parse it as a csv into an array using csvreader or pandas, but that is a separate approach.

if the order is right you can unpack that directly into an employee object using tmpemployee = Employee(*item.split(';'))

Answer 4

You can use the csv.reader method with ; as the delimiter, but slice only the first 3 items of each row since you have a redundant trailing ; on each line of the input:

import csv
with open("test.txt", "r") as f:
    myArrayWithObjects = [Employee(*row[:3]) for row in csv.reader(delimiter=';')]