脚本怎样拆分大文本文件

wen 实用脚本 2026-06-29 27

本文目录导读：

脚本怎样拆分大文本文件

Linux/Unix 命令行工具
Python 脚本
Bash 脚本（跨平台）
Windows PowerShell 脚本
使用 awk 工具
大型文件内存优化版本
选择建议
注意事项

拆分大文本文件有多种方法,具体取决于你的需求和操作系统，以下是几种常见的方案：

Linux/Unix 命令行工具

使用 `split` 命令（最常用）

# 按行数拆分（每10000行一个文件）
split -l 10000 large_file.txt output_prefix_
# 按文件大小拆分（每个文件100MB）
split -b 100M large_file.txt output_prefix_
# 按行数拆分并保留原始扩展名
split -l 10000 large_file.txt output_ --additional-suffix=.txt

使用 `csplit` 命令（按内容拆分）

# 按正则表达式拆分
csplit large_file.txt /pattern/ {*}

Python 脚本

按行数拆分

#!/usr/bin/env python3
import os
def split_file_by_lines(input_file, lines_per_file=10000):
    """按行数拆分大文件"""
    with open(input_file, 'r', encoding='utf-8') as f:
        file_count = 1
        current_lines = []
        for line in f:
            current_lines.append(line)
            if len(current_lines) >= lines_per_file:
                write_chunk(input_file, current_lines, file_count)
                file_count += 1
                current_lines = []
        # 处理最后剩余的行
        if current_lines:
            write_chunk(input_file, current_lines, file_count)
def write_chunk(original_file, lines, chunk_num):
    """写入分片文件"""
    base_name = os.path.splitext(original_file)[0]
    output_file = f"{base_name}_part{chunk_num:04d}.txt"
    with open(output_file, 'w', encoding='utf-8') as f:
        f.writelines(lines)
    print(f"Created: {output_file} ({len(lines)} lines)")
# 使用示例
split_file_by_lines('large_file.txt', lines_per_file=10000)

按文件大小拆分

#!/usr/bin/env python3
import os
import math
def split_file_by_size(input_file, chunk_size_mb=100):
    """按文件大小拆分"""
    chunk_size_bytes = chunk_size_mb * 1024 * 1024
    file_size = os.path.getsize(input_file)
    num_chunks = math.ceil(file_size / chunk_size_bytes)
    with open(input_file, 'rb') as f:
        for i in range(num_chunks):
            chunk_data = f.read(chunk_size_bytes)
            base_name = os.path.splitext(input_file)[0]
            output_file = f"{base_name}_part{i+1:04d}.txt"
            with open(output_file, 'wb') as out:
                out.write(chunk_data)
            print(f"Created: {output_file} ({len(chunk_data)} bytes)")
# 使用示例
split_file_by_size('large_file.txt', chunk_size_mb=100)

Bash 脚本（跨平台）

#!/bin/bash
# 拆分大文本文件的 Shell 脚本
INPUT_FILE="large_file.txt"
LINES_PER_FILE=10000
PREFIX="split_part"
# 检查文件是否存在
if [ ! -f "$INPUT_FILE" ]; then
    echo "Error: File $INPUT_FILE not found"
    exit 1
fi
echo "Splitting $INPUT_FILE..."
# 获取总行数
TOTAL_LINES=$(wc -l < "$INPUT_FILE")
echo "Total lines: $TOTAL_LINES"
# 计算文件数量
NUM_FILES=$(( (TOTAL_LINES + LINES_PER_FILE - 1) / LINES_PER_FILE ))
echo "Will create $NUM_FILES files"
# 拆分文件
split -l $LINES_PER_FILE "$INPUT_FILE" "${PREFIX}_"
# 重命名文件
count=1
for file in ${PREFIX}_*; do
    if [ -f "$file" ]; then
        mv "$file" "${PREFIX}_$(printf %04d $count).txt"
        echo "Created: ${PREFIX}_$(printf %04d $count).txt"
        ((count++))
    fi
done
echo "Split complete!"

Windows PowerShell 脚本

# 按行数拆分
$inputFile = "large_file.txt"
$linesPerFile = 10000
$prefix = "split_part"
$stream = [System.IO.StreamReader]::new($inputFile)
$fileCount = 1
$lineCount = 0
$output = [System.IO.StreamWriter]::new("${prefix}_$( '{0:D4}' -f $fileCount).txt")
while ($stream.Peek() -ge 0) {
    $line = $stream.ReadLine()
    $output.WriteLine($line)
    $lineCount++
    if ($lineCount -ge $linesPerFile) {
        $output.Close()
        $fileCount++
        $output = [System.IO.StreamWriter]::new("${prefix}_$( '{0:D4}' -f $fileCount).txt")
        $lineCount = 0
    }
}
$output.Close()
$stream.Close()
Write-Host "Created $fileCount files"

使用 awk 工具

# 每10000行拆分一个文件
awk 'NR%10000==1{x="filename_"++i".txt"}{print > x}' large_file.txt

大型文件内存优化版本

#!/usr/bin/env python3
import os
import sys
def chunk_file_read(input_file, chunks, chunk_size=4096):
    """内存友好的分块读取器"""
    with open(input_file, 'rb') as f:
        while True:
            chunk = f.read(chunk_size)
            if not chunk:
                break
            yield chunk
def split_large_file_fast(input_file, lines_per_file=10000):
    """高效拆分大文件（优化版）"""
    base_name = os.path.splitext(input_file)[0]
    file_count = 1
    line_count = 0
    with open(input_file, 'r', encoding='utf-8') as f:
        current_lines = []
        for line in f:
            current_lines.append(line)
            line_count += 1
            if line_count >= lines_per_file and len(current_lines) >= lines_per_file:
                output_file = f"{base_name}_part{file_count:04d}.txt"
                with open(output_file, 'w', encoding='utf-8') as out:
                    out.writelines(current_lines)
                print(f"Written: {output_file}")
                current_lines = []
                line_count = 0
                file_count += 1
        # 处理最后剩余的行
        if current_lines:
            output_file = f"{base_name}_part{file_count:04d}.txt"
            with open(output_file, 'w', encoding='utf-8') as out:
                out.writelines(current_lines)
            print(f"Written: {output_file} (final)")
if __name__ == "__main__":
    if len(sys.argv) < 2:
        print("Usage: python split_file.py <input_file> [lines_per_file]")
        sys.exit(1)
    input_file = sys.argv[1]
    lines_per_file = int(sys.argv[2]) if len(sys.argv) > 2 else 10000
    split_large_file_fast(input_file, lines_per_file)

选择建议

方法	优点	适用场景
`split` 命令	最快、最简单	Unix/Linux 系统
Python 脚本	跨平台、灵活	Windows/Linux/Mac
Bash 脚本	自动化方便	Linux 系统
PowerShell	Windows 集成	Windows 系统
awk	轻量级	Unix/Linux 快速任务