在文件文件分割，在进行合并

import sys
import os

class file_openate:
    def __init__(self):
        self.chunksize = int(1024*1024*5)
        self.fromfile = '/root/mysql-5.7.25-el7-x86_64.tar.gz'
        self.todir = '/tmp/split-file/'
        self.partnum = 0

    def check(self):
        if not os.path.exists(self.todir):
            os.makedirs(self.todir)

    def split(self):
        if len(sys.argv) == 2:
            self.fromfile = sys.argv[1]
        if not os.path.isfile(self.fromfile):
            print('文件不存在')
            return
        fread = open(self.fromfile, 'rb')
        while True:
            chunk = fread.read(self.chunksize)
            if not chunk:
                break
            self.partnum += 1
            filename = ('%s/part-%s') % (self.todir, str(self.partnum).rjust(3, '0'))
            fileobj = open(filename, 'wb')
            fileobj.write(chunk)
            fileobj.close()

    def merge(self):
        outfile = open(self.fromfile, 'wb')
        files = os.listdir(self.todir)
        files.sort()
        for file in files:
            print(file)
            filepath = os.path.join(self.todir, file)
            infile = open(filepath, 'rb')
            data = infile.read()
            outfile.write(data)
            infile.close()
        outfile.close()

if __name__ == "__main__":
    fileop = file_openate()
    fileop.check()
    # fileop.split()
    fileop.merge()