如何分块具有特定大小和条件的大文件

Question

我有一个大文本文件。我将该文件分块为具有一定大小的小文件。以下是我得到的一个例子：

import math
import os

numThread = 4
inputData= 'dir\example.txt'

def chunk_files():
    nline = sum(1 for line in open(inputData,'r', encoding='utf-8', errors='ignore'))
    chunk_size = math.floor(nline/int(numThread ))
    n_thread = int(numThread )
    j = 0
    with open(inputData,'r', encoding='utf-8', errors='ignore') as file_:
        for i, line in enumerate(file_):
            if (i + 1 == j * chunk_size and j != n_thread) or i == nline:
                out.close()
            if i + 1 == 1 or (j != n_thread and i + 1 == j * chunk_size):
                chunk_file = '_raw' + str(j) + '.txt'
                if os.path.isfile(chunk_file):
                    break
                out = open(chunk_file, 'w+', encoding='utf-8', errors='ignore')
                j = j + 1
            if out.closed != True:
                out.write(line)
            if i % 1000 == 0 and i != 0:
                print ('Processing line %i ...' % (i))
         print ('Done.')

这是文本文件中的文本示例：

190219 7:05:30 line3 success 
               line3 this is the 1st success process
               line3 this process need 3sec
200219 9:10:10 line2 success 
               line2 this is the 1st success process

由于块的大小，我获得了各种形式的拆分文本。像这样：

190219 7:05:30 line3 success line3 this is the 1st success process

line3 this process need 3sec 200219 9:10:10 line2 success line2 this is the 1st success process

我需要使用正则表达式 reg= re.compile(r"\b(\d{6})(?=\s\d{1,}:\d{2}:\d{2})\b") 拆分后跟日期时间，如下所示：

190219 7:05:30 line3 success line3 this is the 1st success process line3 this process need 3sec

200219 9:10:10 line2 success line2 this is the 1st success process

我试过Python: regex match across file chunk boundaries。但似乎我无法根据我的问题进行调整。

谁能帮我将正则表达式放入 chunk_files 函数中？提前致谢

Answer 1

我相信，让事情变得简单会有很大帮助。

all_parts = []
part = []
for line in l.split('\n'):
    if re.search(r"^\d+\s\d+:\d+:\d+\s", line):
        if part:
            all_parts.append(part)
            part = []
    part.append(line)
else: 
    all_parts.append(part)


print(all_parts)

用你的 test_str 试试这个结果：

In [37]: all_parts                                                                                                                                                                                
Out[37]: 
[['190219 7:05:30 line3 success ',
  '               line3 this is the 1st success process',
  '               line3 this process need 3sec'],
 ['200219 9:10:10 line2 success ',
  '               line2 this is the 1st success process'],
 ['190219 7:05:30 line3 success ',
  '               line3 this is the 1st success process',
  '               line3 this process need 3sec'],
 ['200219 9:10:10 line2 success ',
  '               line2 this is the 1st success process'],
 ['200219 9:10:10 line2 success ',
  '               line2 this is the 1st success process',
  '               line2 this is the 1st success process',
  '               line2 this is the 1st success process',
  '               line2 this is the 1st success process',
  '               line2 this is the 1st success process',
  '               line2 this is the 1st success process']]

然后您可以让代码返回一个生成器/迭代器，您可以在其中轻松地分块任何大小的文件并获取分块行的列表。

Answer 2

由于我们的行数似乎不是静态的，我们也许可以得到 6 位数字和日期，然后收集我们所有的行，然后我们编写剩下的问题的脚本，也许这个简单的表达式会在这里引起我们的兴趣：

(\d{6})\s(\d{1,}:\d{2}:\d{2})|\s*(.*)\s*

这里有我们的数字部分：

(\d{6})\s(\d{1,}:\d{2}:\d{2})

还有我们的台词：

\s*(.*)\s*

Demo

测试

# coding=utf8
# the above tag defines encoding for this document and is for Python 2.x compatibility

import re

regex = r"(\d{6})\s(\d{1,}:\d{2}:\d{2})|\s*(.*)\s*"

test_str = ("190219 7:05:30 line3 success \n"
    "               line3 this is the 1st success process\n"
    "               line3 this process need 3sec\n"
    "200219 9:10:10 line2 success \n"
    "               line2 this is the 1st success process\n"
    "190219 7:05:30 line3 success \n"
    "               line3 this is the 1st success process\n"
    "               line3 this process need 3sec\n"
    "200219 9:10:10 line2 success \n"
    "               line2 this is the 1st success process\n"
    "200219 9:10:10 line2 success \n"
    "               line2 this is the 1st success process\n"
    "               line2 this is the 1st success process\n"
    "               line2 this is the 1st success process\n"
    "               line2 this is the 1st success process\n"
    "               line2 this is the 1st success process\n"
    "               line2 this is the 1st success process")

matches = re.finditer(regex, test_str, re.MULTILINE)

for matchNum, match in enumerate(matches, start=1):

    print ("Match {matchNum} was found at {start}-{end}: {match}".format(matchNum = matchNum, start = match.start(), end = match.end(), match = match.group()))

    for groupNum in range(0, len(match.groups())):
        groupNum = groupNum + 1

        print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = match.start(groupNum), end = match.end(groupNum), group = match.group(groupNum)))

# Note: for Python 2.7 compatibility, use ur"" to prefix the regex and u"" to prefix the test string and substitution.

输出

Match 1 was found at 0-14: 190219 7:05:30
Group 1 found at 0-6: 190219
Group 2 found at 7-14: 7:05:30
Group 3 found at -1--1: None
Match 2 was found at 14-45:  line3 success 

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 15-29: line3 success 
Match 3 was found at 45-98: line3 this is the 1st success process

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 45-82: line3 this is the 1st success process
Match 4 was found at 98-127: line3 this process need 3sec

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 98-126: line3 this process need 3sec
Match 5 was found at 127-141: 200219 9:10:10
Group 1 found at 127-133: 200219
Group 2 found at 134-141: 9:10:10
Group 3 found at -1--1: None
Match 6 was found at 141-172:  line2 success 

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 142-156: line2 success 
Match 7 was found at 172-210: line2 this is the 1st success process

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 172-209: line2 this is the 1st success process
Match 8 was found at 210-224: 190219 7:05:30
Group 1 found at 210-216: 190219
Group 2 found at 217-224: 7:05:30
Group 3 found at -1--1: None
Match 9 was found at 224-255:  line3 success 

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 225-239: line3 success 
Match 10 was found at 255-308: line3 this is the 1st success process

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 255-292: line3 this is the 1st success process
Match 11 was found at 308-337: line3 this process need 3sec

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 308-336: line3 this process need 3sec
Match 12 was found at 337-351: 200219 9:10:10
Group 1 found at 337-343: 200219
Group 2 found at 344-351: 9:10:10
Group 3 found at -1--1: None
Match 13 was found at 351-382:  line2 success 

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 352-366: line2 success 
Match 14 was found at 382-420: line2 this is the 1st success process

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 382-419: line2 this is the 1st success process
Match 15 was found at 420-434: 200219 9:10:10
Group 1 found at 420-426: 200219
Group 2 found at 427-434: 9:10:10
Group 3 found at -1--1: None
Match 16 was found at 434-465:  line2 success 

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 435-449: line2 success 
Match 17 was found at 465-518: line2 this is the 1st success process

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 465-502: line2 this is the 1st success process
Match 18 was found at 518-571: line2 this is the 1st success process

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 518-555: line2 this is the 1st success process
Match 19 was found at 571-624: line2 this is the 1st success process

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 571-608: line2 this is the 1st success process
Match 20 was found at 624-677: line2 this is the 1st success process

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 624-661: line2 this is the 1st success process
Match 21 was found at 677-730: line2 this is the 1st success process

Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 677-714: line2 this is the 1st success process
Match 22 was found at 730-767: line2 this is the 1st success process
Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 730-767: line2 this is the 1st success process
Match 23 was found at 767-767: 
Group 1 found at -1--1: None
Group 2 found at -1--1: None
Group 3 found at 767-767: