Python implements file/folder copying function

1. Introduction to the basic tool library

In Python standard libraryshutilModules are the main tools:

import shutil
import os

2. File copy basics

1. Copy a single file

# Retain metadata (modification time, etc.)shutil.copy2('', '')

# Copy content only('', 'backup/')  # Automatically retain file names
# File flow method (suitable for large files)with open('', 'rb') as src, open('', 'wb') as dst:
    (src, dst, length=16*1024)  #16KB buffer

3. Advanced directory copying

1. Simple directory copying

# Copy the entire directory (the target directory must not exist)('src_dir', 'dst_dir')

# Allow overwrite existing directories (Python 3.8+)('src', 'existing_dir', dirs_exist_ok=True)

2. Customize the copy process

def ignore_patterns(*patterns):
    def _ignore(path, names):
        ignored = []
        for pattern in patterns:
            ((names, pattern))
        return set(ignored)
    return _ignore

# Exclude .pyc files and temporary files('src', 'dst', ignore=ignore_patterns('*.pyc', '*.tmp'))

# Copy with progress callbacksdef copy_progress(src, dst, *, follow_symlinks=True):
    print(f"Copying {src} =&gt; {dst}")

('src', 'dst', copy_function=copy_progress)

4. Advanced custom implementation

When full control of the replication process is required, it can be done manually:

def deep_copy(src, dst, symlinks=False):
    if not (dst):
        (dst)
        (src, dst)
    
    for item in (src):
        src_path = (src, item)
        dst_path = (dst, item)
        
        if (src_path):
            deep_copy(src_path, dst_path, symlinks)
        else:
            if (dst_path):
                if (src_path, dst_path):
                    continue
                (dst_path)
            if symlinks and (src_path):
                linkto = (src_path)
                (linkto, dst_path)
            else:
                shutil.copy2(src_path, dst_path)

5. Key points for exception handling

try:
    ('src', 'dst')
except  as e:
    print(f'Directory not copied. Error: {e}')
except OSError as e:
    print(f'OSError: {}')

6. Performance optimization suggestions

Batch small files: UseThe default implementation of
Extra large file: UsecopyfileobjBlock copy
Network storage: Increase the buffer size (e.g.16*1024*1024That is 16MB)
Parallel processing: Use multi-threaded/multi-process for independent subdirectories

7. Complete sample code

import shutil
import os
from pathlib import Path

def smart_copy(src, dst, overwrite=False, ignore=None):
    """Smart Copyer"""
    src = Path(src)
    dst = Path(dst)

    if src.is_file():
        if dst.is_dir():
            dst = dst / 
        if ():
            if overwrite:
                ()
            else:
                raise FileExistsError(f"{dst} already exists")
        shutil.copy2(str(src), str(dst))
        return

    if not src.is_dir():
        raise ValueError("Source path invalid")

    if ():
        if overwrite:
            if dst.is_dir():
                (dst)
            else:
                ()
        else:
            raise FileExistsError(f"{dst} already exists")

    (
        str(src),
        str(dst),
        symlinks=True,
        ignore=ignore,
        copy_function=shutil.copy2,
        dirs_exist_ok=overwrite
    )

#User Examplesmart_copy(
    '/data/project',
    '/backup/project_2024',
    overwrite=True,
    ignore=shutil.ignore_patterns('*.log', 'temp')
)

Key points description:

usecopy2InsteadcopyFile metadata can be preserved
PathObjects are safer and easier to use than string paths
dirs_exist_okParameters require Python 3.8+
Custom ignore mode supports complex filtering logic
Perfect exception handling ensures operational reliability

This approach can handle the following complex scenarios:

Mixed file types (normal file/symbol link/special file)
Keep all file attributes
Security processing of existing content
Flexible filtering mechanism
Cross-platform compatibility (Windows/Unix)

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