Break CSV into N chunks using Python

csv_chunker.py

from tqdm import tqdm


def chunker(seq, size):
    for pos in range(0, len(seq), size):
        yield seq[pos:pos + size]


with open("input.csv") as csv_fi:
    csv_lines = csv_fi.readlines()

field_names = csv_lines[0].split(",")


for c_i, chunk in enumerate(chunker(csv_lines[1:], len(csv_lines) // 10)):
    with open(f"output-{c_i}.csv", "w") as out_fi:
        out_fi.write(",".join(field_names))

        for row in tqdm(chunk):
            out_fi.write(row)