How to sort a CSV file's column without regard for character casing?

Question

I have a program that randomly generates a series of 5 letters (ASCII, both upper and lower case) in column 1 of a CSV and 4 numbers (0-9) in column 2 of the same CSV. I can sort column 2 in order of ascending values but struggle with column 1 as it sorts all the uppercase values first and then lower case. This is also output to a new file, sorted.csv.

Example:

ANcPI
DLBvA
FpSCo
beMhy
dWDjl

Does anyone know how to sort these so that casing does not have an impact but rather just the letter? It should sort as:

ANcPI
beMhy
DLBvA
dWDjl
FpSCo

Here is the code for the program as it currently stands:

import random
import string

#se='111411468'                                                                             # Hardcoded value for development of the program
se = int(input('Please enter your ID for specific random number sequence: '))               # Asks user for ID number to generate files based on, uses se as above
random.seed(se,2)                                                                           # Use of 2 in random.seed handles strings, numbers and others
ascii_lowercase = 'abcdefghijklmnopqrstuvwxyz'                                              # Uses all lower case ASCII 
ascii_uppercase = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'                                              # Uses all upper case ASCII
ascii_letters = ascii_lowercase + ascii_uppercase                                           # Combines all ASCII characters giving a higher degree of randomness to the generated files
digits = '0123456789'                                                                       # Range of digit values for column 2 of 'unsorted.csv'

def rubbish_string(selection,l):
    s = ''
    for c in range(l):
        s += selection[random.randint(0,len(selection)-1)]
    return s

def writeRandomFile(filename):
    with open(filename, 'w') as fout:                                                      # With automatically closes the file on finishing its extent,even with exceptions
        fout.write('Personal ID,'+str(se)+'\n')                                            # Write and assembled string, personal ID in grid A1 and personal ID No. in grid B1.....headings for the data
        for xc in range(random.randint(10,20)):
            fout.write(rubbish_string(ascii_letters,5)+','+rubbish_string(digits,4)+'\n')  # Assemble and write a line to the file using 5 from the ascii_letters and 4 from the digits variable

def selectionSort (alist, col):                                                            # Slightly modified function for selection sort from part Q7A
    for fillslot in range(len(alist)-1,0,-1):
        positionOfMax=0                                                                    # Initally the maximum value is positioned at 0, Binary so position 1 
        for location in range(1, fillslot+1):
                                                                                           # Results in a list of size 2, first part is letters, second part is numbers
            line1 = alist[location].split(",")                                             # Makes sense to use "," for a .csv
            line2 = alist[positionOfMax].split(",")

                                                                                           # Column-1 because computers count from zero (Binary)
                                                                                           # When the user enters 1 or 2, the computer deals with it in terms of 0 or 1
            if line1[col - 1] > line2[col - 1]:                                            # Deals with the Binary issue by taking 1 from the input column value from the user
                positionOfMax=location

        temp= alist[fillslot]
        alist[fillslot]=alist[positionOfMax]
        alist[positionOfMax]=temp
                                                                                           # Main part...
                                                                                           # Create random file based on the user data
writeRandomFile('unsorted.csv')


                                                                                           # Allow user pick which column to sort on, either 1 or 2 (could be adapted for more columns)
sortOnColumn = -1
while sortOnColumn != 1 and sortOnColumn != 2:                                             # If the user does not enter an appropriate value, in this case 1 or 2 they are re-asked to input the column based on which ths sorting will be done.
    sortOnColumn = int(input("Which column should the files be sorted on?"))
                                                                                           # Open unsorted file and load into a list
fin = open('unsorted.csv', 'r')                                                            # Opens a file for reading, called fin
data = []                                                                                  # Creates an empty list named data
header = next(fin)                                                                         # Skip first line because its Personal ID data, not random data generated by the program
for line in fin:                                                                           # Loops through lines in fin
    data.append(line.strip())                                                          # Adds the line to the list, appending the list[]

selectionSort(data, sortOnColumn)                                                          # Sort list with the selection sort algorithm, calling the function, where data=the list and sortOnColum=user choice


                                                                                           # Write the now sorted list to a file, called fout
fout = open('sorted.csv', 'w')                                                             # Opening the empty sort.csv in write mode
fout.write(header)                                                                         # Write PersonID data first at the top of the .csv as in the unsorted format
for entry in data:                                                                         # Write ordered data
    fout.write(entry)
    data.sort(key=lambda m : m.lower())                                                # Sorts col.1 based on non case sensitive letters but issues with col.2..............
    fout.write("\n")                                                                   # Formating with "\n"
fout.close()                                                                               # Close the file so not to have generated just a blank .csv with no data
print('Your Files Have Been Generated, Goodbye!')

Answer 1

You have a lot of errors in your code as shown on PEP8 online. If you can, use either PyCharm Community or PyCharm Edu in the future so that your code is automatically checked while writing it. Here is a revised version of your code:

import csv
import random
import string
import sys

UNSORTED_FILENAME = 'unsorted.csv'
SORTED_FILENAME = 'sorted.csv'


def main():
    """This function handles execution of the entire program."""
    # seed = setup_random_sequence(111411468)
    seed = setup_random_sequence()
    write_random_file(UNSORTED_FILENAME, seed)
    header, data = load_and_sort(UNSORTED_FILENAME)
    write_csv_file(SORTED_FILENAME, header, data)
    print('Your files have been generated. Goodbye!')


def setup_random_sequence(seed=None):
    """Seed the random number generator with some specific value."""
    if seed is None:
        seed = get_int('Enter your ID for your random number sequence: ')
    random.seed(seed, 2)
    return seed


def get_int(prompt='>>> '):
    """Get an integer from the user and return it to the function's caller."""
    while True:
        try:
            text = input(prompt)
        except EOFError:
            sys.exit()
        else:
            try:
                return int(text)
            except ValueError:
                print('You must enter an integer.')


def write_random_file(filename, seed):
    """Create random file based on the user data."""
    rows = ((rubbish_string(string.ascii_letters, 5),
             rubbish_string(string.digits, 4))
            for _ in range(random.randint(10, 20)))
    write_csv_file(filename, ('Personal ID', seed), rows)


def write_csv_file(filename, header, data):
    """Write the now sorted list to a file."""
    with open(filename, 'w', newline='') as file:
        writer = csv.writer(file)
        writer.writerow(header)
        writer.writerows(data)


def rubbish_string(selection, length):
    """Create a string of given length built of characters from selection."""
    return ''.join(random.choice(selection) for _ in range(length))


def load_and_sort(filename):
    """Load the file given by filename and sort by user specification."""
    sort_on_column = None
    while True:
        sort_on_column = get_int('Which column should file be sorted on? ')
        if sort_on_column in {1, 2}:
            break
        print('Column number is out of range.')
    with open(filename, newline='') as file:
        reader = csv.reader(file)
        header = next(reader)
        data = list(reader)
    selection_sort(data, sort_on_column)
    return header, data


def selection_sort(array, column):
    """This is a modified function for selection sort from part Q7A."""
    array.sort(key=lambda row: row[column - 1].casefold())

if __name__ == '__main__':
    main()

As you might notice on PEP8 online, the code no longer has any errors. If you need any further changes, please let me know.