如何將大文字檔(~GB)分割成多個小檔案

有時候模擬出來的資料檔過大，文字編輯器打不開或開啟過於緩慢，則可以將大檔案分割成小檔案以利操作。

# -*- coding: utf-8 -*-
"""
Created on Tue Apr 20 14:41:43 2021

@author: mlin
"""

big_file_path = 'd:/demo/0000_CPA_Sim_1.sp'
filesize_MB = 100

# Don't Change Code Below-------------------------------------
import os

N = filesize_MB * (2 ** 20)
n = 0
num = 1
data = []
output_dir = os.path.dirname(big_file_path)

with open(big_file_path) as fin:
    name = '{}/part0.txt'.format(output_dir)
    fout = open(name, 'w')
    for i in fin:
        if n / N > 1:
            print(fout)
            fout.close()

            name = '{}/part{}.txt'.format(output_dir, num)
            fout = open(name, 'w')

            num += 1
            n = 0

        fout.writelines(i)
        n += len(i)

(圖一) 分割檔案