csv_splitter.py

import random
import math
import os

PATH=os.getcwd()
print("This is where the train, val and test files will be at  {}".format(PATH))


DATASET_FILE = '/home/Pictures/udacity_driving_datasets/labels_trainval.csv'
FILE_TRAIN = os.path.join(PATH, 'train.csv')
FILE_VALID = os.path.join(PATH, 'validation.csv')
FILE_TESTS = os.path.join(PATH, 'test.csv')

# Set to true if you want to copy first line from main
# file into each split (like CSV header)
IS_CSV = True

# Make sure it adds to 100, no error checking below
PERCENT_TRAIN = 60
PERCENT_VALID = 20
PERCENT_TESTS = 20

data = [l for l in open(DATASET_FILE, 'r')]

train_file = open(FILE_TRAIN, 'w')
valid_file = open(FILE_VALID, 'w')
tests_file = open(FILE_TESTS, 'w')

if IS_CSV:
    train_file.write(data[0])
    valid_file.write(data[0])
    tests_file.write(data[0])
    data = data[1:len(data)]

num_of_data = len(data)
num_train = int((PERCENT_TRAIN/100.0)*num_of_data)
num_valid = int((PERCENT_VALID/100.0)*num_of_data)
num_tests = int((PERCENT_TESTS/100.0)*num_of_data)

print("No of rows in Dataset is {}".format(num_of_data))
print("No of rows in Train Dataset is {}".format(num_train))
print("No of rows in Validation Dataset is {}".format(num_valid))
print("No of rows in Test Dataset is {}".format(num_tests))

data_fractions = [num_train, num_valid, num_tests]
split_data = [[],[],[]]

rand_data_ind = 0

for split_ind, fraction in enumerate(data_fractions):
    for i in range(fraction):
        rand_data_ind = random.randint(0, len(data)-1)
        split_data[split_ind].append(data[rand_data_ind])
        data.pop(rand_data_ind)

for l in split_data[0]:
    train_file.write(l)
    
for l in split_data[1]:
    valid_file.write(l)
    
for l in split_data[2]:
    tests_file.write(l)
    
train_file.close()
valid_file.close()
tests_file.close()

1. Replace DATASET_FILE with your file path
2. train.csv, validation.csv, test.csv will be created at the current working directory
3. IS_CSV=True will copy the header to all the splits
4. IS_CSV=False for ignoring the header to all splits
5. Specify percentage of split at PERCENT_TRAIN, PERCENT_VALID, PERCENT_TEST .Make sure the sum is 100
6. Check the current working directory for the new created csv files.
7. Happy coding