Python 文件处理：从基础操作到高级技巧的全面指南

# 打开文件
file_path = 'example.txt'
file = open(file_path, 'r')  # 'r' 表示读取模式

# 读取文件内容
content = file.read()
print(content)

# 关闭文件
file.close()

# 以写入模式打开文件
file = open('example_write.txt', 'w')

# 写入内容
file.write('Hello, this is a sample text.')

# 关闭文件
file.close()

# 使用上下文管理器打开文件
with open('example.txt', 'r') as file:
    content = file.read()
    print(content)
# 文件自动关闭，不再需要调用 file.close()

# 读取文本文件
with open('text_file.txt', 'r') as file:
    lines = file.readlines()
    for line in lines:
        print(line.strip())  # strip() 去除换行符和空白

# 写入文本文件
with open('new_text_file.txt', 'w') as file:
    file.write('This is a new line.\n')
    file.write('Another line here.\n')

import csv

# 读取 CSV 文件
with open('data.csv', 'r') as csvfile:
    reader = csv.reader(csvfile)
    for row in reader:
        print(row)

# 写入 CSV 文件
data = [['Name', 'Age'], ['Alice', 25], ['Bob', 30], ['Charlie', 22]]
with open('new_data.csv', 'w', newline='') as csvfile:
    writer = csv.writer(csvfile)
    writer.writerows(data)

# 逐行读取大型文件
with open('large_file.txt', 'r') as file:
    for line in file:
        process_line(line)

# 内存映射文件
import mmap

with open('large_file.txt', 'r') as file:
    with mmap.mmap(file.fileno(), length=0, access=mmap.ACCESS_READ) as mmapped_file:
        data = mmapped_file.read()
        process_data(data)

import os

# 遍历目录中的文件和子目录
for root, dirs, files in os.walk('/path/to/directory'):
    for file in files:
        print(os.path.join(root, file))

import os

# 获取文件大小
file_size = os.path.getsize('example.txt')
print(f'File size: {file_size} bytes')

# 获取文件创建时间
creation_time = os.path.getctime('example.txt')
print(f'File created at: {creation_time}')

# 检查文件是否存在
file_exists = os.path.exists('example.txt')
print(f'File exists: {file_exists}')

import re

pattern = re.compile(r'\b\d{3}-\d{2}-\d{4}\b')  # 匹配美国社会安全号码

with open('text_with_ssns.txt', 'r') as file:
    content = file.read()
    matches = pattern.findall(content)
    print(matches)

import shutil

# 复制文件
shutil.copy('source_file.txt', 'destination_folder/')

# 移动文件
shutil.move('source_file.txt', 'destination_folder/')

# 删除文件夹及其内容
shutil.rmtree('folder_to_delete/')