对python数据切割归并算法的实例讲解

 def get_file_lines(file_path): # 目标文件的路径 file_path = str(file_path) with open(file_path, 'rb') as file: # 定义行数 i = 0 while True: # 一次读取一行数据 line = file.readline() if not line : break else: # 每读一行，行数加一 i += 1 #设置进度条，每当i读取1000000行时打印一次i # 每当读取1000000的整数倍行时，打印行数（进度条） if i % 1000000 == 0: print(i) # 打印总行数 print(i) return i 

 # 定义均等切割函数，num是待切割的文件的行数的值，n为切割份数,file_path是待切割的文件，file_dir是切割好的文件写入的目录 def evg_split(num, n, file_path, file_dir): last_list = [] # 如果样本刚好可以整除为n份 if num % n == 0: for i in range(n): # 则直接将样本分为n分没份对应num/n个 last_list.append(num / n) # 如果不能整除 if num % n != 0: # 如果不能整除，则先将num整除n-1并取n-1份,余下的单独做一份 evg = (num - num % n) // (n - 1) for i in range(n): last_list.append(evg) last_list.append(num % (n - 1)) print(last_list) # return last_list # 对应于切割后的每一份数据 with open(file_path, 'rb') as path: for i in range(n): # 创建临时文件 tmp_file = file_dir + str(i) + '.txt' # 打开临时文件，将内容一条一条的写入 file = open(tmp_file, 'wb') for j in range(int(last_list[i])): line = path.readline() file.write(line) print(line) print('------------') file.close() 

 def merge( mylist1, mylist2, file1): while len(mylist1) > 0 and len(mylist2) > 0: if mylist1[0] mylist2[0]: with open(file1,'a') as file: file.write(str(mylist2[0])) del mylist2[0] else: with open(file1,'a') as file: file.write(str(mylist1[0])) file.write(str(mylist2[0])) del mylist1[0] del mylist2[0] with open(file1, 'a') as file: for i in mylist1: file.write(str(i)) for i in mylist2: file.write(str(i))