notation

[MCL169]

I often use generators to process something line by line or element by element.
To convert a date, you should read the docs: https://docs.python.org/3/library/dateti...e.strptime

An example:

import io
from datetime import date as Date
from datetime import datetime as DateTime

# 10 lines of fake data
fake_file = io.StringIO("19260701,0.09,-0.22,-0.30,0.009\n" * 10)


def transformer(file):
    """
    Generator to exctract line by line data from a file.
    The seperator is a `,` and the first colum is a date formatted as: `YYYYMMDD`
    The remaing columns are converted to float.
    """
    # iterating over a file-object yields lines
    # and the line ending is kept
    for line in fake_file:
        # date is the first element of row
        # and *rest consumes all remaining elements
        # (rest is a list)
        # rstrip removes tailing whitespaces
        date, *rest = line.rstrip().split(",")
        # converting all elements from rest to float
        values = list(map(float, rest))

        # extracting the date
        # a regex could be used
        # but in this example I use slicing
        # year, month, day = map(int, (date[0:4], date[4:6], date[6:8]))
        # date = Date(year, month, day)

        # Another method to parse date on a single line
        date = DateTime.strptime(date, "%Y%m%d").date()
        # using iterable unpacking to get a flat list with
        # date, value1, value2, value3, ...
        yield [date, *values]


for row in transformer(fake_file):
    print(row)

Output:
[datetime.date(1926, 7, 1), 0.09, -0.22, -0.3, 0.009]
[datetime.date(1926, 7, 1), 0.09, -0.22, -0.3, 0.009]
[datetime.date(1926, 7, 1), 0.09, -0.22, -0.3, 0.009]
[datetime.date(1926, 7, 1), 0.09, -0.22, -0.3, 0.009]
[datetime.date(1926, 7, 1), 0.09, -0.22, -0.3, 0.009]
[datetime.date(1926, 7, 1), 0.09, -0.22, -0.3, 0.009]
[datetime.date(1926, 7, 1), 0.09, -0.22, -0.3, 0.009]
[datetime.date(1926, 7, 1), 0.09, -0.22, -0.3, 0.009]
[datetime.date(1926, 7, 1), 0.09, -0.22, -0.3, 0.009]
[datetime.date(1926, 7, 1), 0.09, -0.22, -0.3, 0.009]

All good stuff. Now to utilize within my professors detailed instructions. lol