import csv

def csv_to_list(csv_file, delimiter=','):
    """ 
    Reads in a CSV file and returns the contents as list,
    where every row is stored as a sublist, and each element
    in the sublist represents 1 cell in the table.
    
    """
    with open(csv_file, 'r') as csv_con:
        reader = csv.reader(csv_con, delimiter=delimiter)
        return list(reader)

csv_cont = csv_to_list('../Data/test.csv')

print('first 3 rows:')
for row in range(3):
    print(csv_cont[row])

def print_csv(csv_content):
    """ Prints CSV file to standard output."""
    print(50*'-')
    for row in csv_content:
        row = [str(e) for e in row]
        print('\t'.join(row))
    print(50*'-')

csv_cont = csv_to_list('../Data/test.csv')

print('\n\nOriginal CSV file:')
print_csv(csv_cont)

def convert_cells_to_floats(csv_cont):
    """ 
    Converts cells to floats if possible
    (modifies input CSV content list).
    
    """
    for row in range(len(csv_cont)):
        for cell in range(len(csv_cont[row])):
            try:
                csv_cont[row][cell] = float(csv_cont[row][cell])
            except ValueError:
                pass 

print('first 3 rows:')
for row in range(3):
    print(csv_cont[row])

import operator

def sort_by_column(csv_cont, col, reverse=False):
    """ 
    Sorts CSV contents by column name (if col argument is type <str>) 
    or column index (if col argument is type <int>). 
    
    """
    header = csv_cont[0]
    body = csv_cont[1:]
    if isinstance(col, str):  
        col_index = header.index(col)
    else:
        col_index = col
    body = sorted(body, 
           key=operator.itemgetter(col_index), 
           reverse=reverse)
    body.insert(0, header)
    return body

csv_cont = csv_to_list('../Data/test.csv')

print('\n\nOriginal CSV file:')
print_csv(csv_cont)

print('\n\nCSV sorted by column "column3":')
convert_cells_to_floats(csv_cont)
csv_sorted = sort_by_column(csv_cont, 'column3')
print_csv(csv_sorted)

def mark_minmax(csv_cont, col, mark_max=True, marker='*'):
    """
    Sorts a list of CSV contents by a particular column 
    (see sort_by_column function).
    Puts a marker on the maximum value if mark_max=True,
    or puts a marker on the minimum value mark_max=False
    (modifies input CSV content list).
    
    """
    
    sorted_csv = sort_by_column(csv_cont, col, reverse=mark_max)
    if isinstance(col, str):  
        col_index = sorted_csv[0].index(col)
    else:
        col_index = col
    sorted_csv[1][col_index] = str(sorted_csv[1][col_index]) + marker
    return None

def mark_all_col(csv_cont, mark_max=True, marker='*'):
    """
    Marks all maximum (if mark_max=True) or minimum (if mark_max=False)
    values in all columns of a CSV contents list - except the first column.
    Returns a new list that is sorted by the names in the first column
    (modifies input CSV content list).
    
    """
    for c in range(1, len(csv_cont[0])):
        mark_minmax(csv_cont, c, mark_max, marker)
    marked_csv = sort_by_column(csv_cont, 0, False)
    return marked_csv

import copy

csv_cont = csv_to_list('../Data/test.csv')

csv_marked = copy.deepcopy(csv_cont)
convert_cells_to_floats(csv_marked)
mark_all_col(csv_marked, mark_max=False, marker='*')
print_csv(csv_marked)
print('*: min-value')

def write_csv(dest, csv_cont):
    """ Writes a comma-delimited CSV file. """

    with open(dest, 'w') as out_file:
        writer = csv.writer(out_file, delimiter=',')
        for row in csv_cont:
            writer.writerow(row)

write_csv('../Data/test_marked.csv', csv_marked)

csv_cont = csv_to_list('../Data/test_marked.csv')

print('\n\nWritten CSV file:')
print_csv(csv_cont)

import os

in_dir = '../Data'
out_dir = '../Data/processed'
csvs = [
    (os.path.join(in_dir, csv), 
        os.path.join(out_dir, csv))
    for csv in os.listdir(in_dir) 
    if csv.endswith('.csv')
    ]

for i in csvs:
    print(i)

def process_csv(csv_in, csv_out):
    """ 
    Takes an input- and output-filename of an CSV file
    and marks minimum values for every column.
    
    """
    csv_cont = csv_to_list(csv_in)
    csv_marked = copy.deepcopy(csv_cont)
    convert_cells_to_floats(csv_marked)
    mark_all_col(csv_marked, mark_max=False, marker='*')
    write_csv(csv_out, csv_marked)

for inout in csvs:
    process_csv(inout[0], inout[1])