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I'm new to Python so the answer to this question is probably easy. I've done some coding in it before, but I forgot most of it.

I have an list of values, that I get from a file like this:

podela = fobj.read().split()

There are 10 values that as a whole represent some data. These 10 values repeat N times. So, Nx10 values all together. Only some values (4 out of 10) are used to create an instance of the following class.

I have a class that represents time:

class Vreme:
    day = 0
    hour = 0
    minute = 0
    second = 0

    def __init__(self, day, hour, minute, second):
        self.day = day
        self.hour = hour
        self.minute = minute
        self.second = second
    def __init__(self):
        self.day = 0
        self.hour = 0
        self.minute = 0
        self.second = 0

    def toString(self):
        s = repr(self.day)+'-'+repr(self.hour)+':'+repr(self.minute)+':'+repr(self.second)
        return s

    def print(self):
        s = self.toString()
        print(s)

How can I instantiate a list of instances of Vreme using the list podela?

EDIT1: podela holds the values, which are hex representations in a string format.

Part of the file example, 4xlines:

4a 02 f6 01 00 04 0e 08 03 00
4a 02 f6 01 00 04 0e 08 04 00
49 02 f6 01 00 04 0e 08 04 00
49 02 f5 01 00 04 0e 08 04 00
4a 02 f6 01 00 04 0e 08 05 00

podela after split, few last values:

'0e', '12', '1f', '00', '49', '02', 'f4', '01', '00', '04', '0e', '12', '20', '00', '49', '02', 'f5', '01', '00', '04', '0e', '12', '20', '00', '48', '02', 'f4', '01', '00', '04', '0e', '12', '20', '00', '4a', '02', 'f4', '01', '00', '04', '0e', '12', '21', '00', '49', '02', 'f5', '01', '00', '04', '0e', '12', '21', '00', '4a', '02', 'f5', '01', '00', '04', '0e', '12', '22', '00', '49', '02', 'f5', '01', '00', '04', '0e', '12', '22', '00', '48', '02', 'f4', '01', '00', '04', '0e', '12', '22', '00', '4a', '02', 'f6', '01', '00', '04', '0e', '12', '23', '00', '48', '02', 'f4', '01', '00', '04', '0e', '12', '23', '00']

Input file (that gets split for podela) is 56kB, but this is a test file. Real files will be 5MB+

EDIT2: Example of input and output Example is with a really small file, that holds 3x10 values.

The file holds these values:

00 00 00 00 00 00 00 00 00 00
01 02 03 04 05 06 07 08 09 10
11 11 11 11 11 11 11 11 11 11

When podela is made, each of these values is a member of an array

podela = [00 00 00 00 00 00 00 00 00 00 01 02 03 04 05 06 07 08 09 10 11 11 11 11 11 11 11 11 11 11]

Lets say that I use values at positions 0, 2, 4 and 8 for a constructor. vreme should be a list of 3 instances of Vreme:

vreme[0] = 00 00 00 00
vreme[1] = 01 03 05 07
vreme[2] = 11 11 11 11
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4
  • 1
    What does podela look like? Post a sample please. Commented May 10, 2018 at 13:06
  • 1
    why do you have two __init__ methods? Commented May 10, 2018 at 13:07
  • so what part of your example represents days, minutes, etc.? Commented May 10, 2018 at 13:20
  • @IvanVinogradov I have two inits, cause I don't know python. I was trying different stuff, and that is from that time. As I see, i need only one constructor. Values are at positions 6, 7, 8 and 9 (day, hour, minute, second). For example, for first data set of 10 values, i need to extract 04 0e 08 03 Commented May 10, 2018 at 13:27

2 Answers 2

Reset to default
1

Maybe you can just append them in a for loop

vreme_instances = []
for i in podela:
    vreme_instances.append(Vreme(i[0], i[2], i[4], i[8]))  
    # change indexes at the line above as you need

assuming that podela is the list of tuples like this:

podela = [(4, 12, 32, 54), (16, 20, 12, 32)]
# [(day, hour, minute, second),]

Edit

To achieve the above result, first change this 

podela = fobj.read().split()

to this 

lines = fobj.read().splitlines()     # first: split input file into lines
podela = [x.split() for x in lines]  # second: split every line to values

That will give you a list of N sublists:

[
    ['4a', '02', 'f6', '01', '00', '04', '0e', '08', '03', '00'], 
    ['4a', '02', 'f6', '01', '00', '04', '0e', '08', '04', '00'], 
    ['49', '02', 'f6', '01', '00', '04', '0e', '08', '04', '00'], 
    ['49', '02', 'f5', '01', '00', '04', '0e', '08', '04', '00'],
]

Each sublist represents a Vreme instance.

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2 Comments

Hmmm i guess i can. I though there is a "one-line" solution. I know that I can do it with indexes, but that didn't really sound "python-like" to me. On the other hand, I have little to no clue how to work in Python, so I'm probably wrong
Thank you very much, the exact thing I needed
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First, I recommend consolidating your two init functions into a single one like so:

class Vreme:
    day = 0
    hour = 0
    minute = 0
    second = 0

    def __init__(self, day=0, hour=0, minute=0, second=0):
        self.day = day
        self.hour = hour
        self.minute = minute
        self.second = second

    def toString(self):
        s = repr(self.day)+'-'+repr(self.hour)+':'+repr(self.minute)+':'+repr(self.second)
        return s

    def print(self):
        s = self.toString()
        print(s)

Then you can instantiate it as:

vreme = Vreme(*podela[:4])

assuming you want the first 4 elements of podela

Example:

podela = [1, 2, 3, 4, 5, 6]
vreme = Vreme(*podela[:4])

print(vreme.day)
# 1

print(vreme.hour)
# 2

print(vreme.minute)
# 3

print(vreme.second)
# 4
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1 Comment

How can I get a list of vreme? I'll edit the question to include example of input/output

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