File & I/O Operations

def atomic_save(dest_path, **kwargs):
    """
    Atomic file saving with backup options.
    
    Parameters:
    - dest_path (str): Destination file path
    - text_mode (bool): Open in text mode (default: True)
    - backup (bool): Create backup before overwrite
    - part_file (str): Temporary file suffix
    
    Returns:
    AtomicSaver: Context manager for atomic operations
    """

class AtomicSaver:
    """Context manager for atomic file writing operations."""
    def __init__(self, dest_path, **kwargs): ...
    def __enter__(self): ...
    def __exit__(self, exc_type, exc_val, exc_tb): ...

def mkdir_p(path):
    """
    Create directory including parent directories (like mkdir -p).
    
    Parameters:
    - path (str): Directory path to create
    
    Returns:
    None
    """

def copy_tree(src, dst, symlinks=False, ignore=None):
    """
    Copy directory trees.
    
    Parameters:
    - src (str): Source directory
    - dst (str): Destination directory
    - symlinks (bool): Copy symlinks as symlinks
    - ignore (callable): Function to ignore certain files
    
    Returns:
    None
    """

def iter_find_files(directory, patterns, **kwargs):
    """
    Iterator for finding files matching patterns.
    
    Parameters:
    - directory (str): Directory to search
    - patterns (list): List of glob patterns
    
    Yields:
    str: Matching file paths
    """

def path_to_unicode(path):
    """
    Convert path to unicode string.
    
    Parameters:
    - path: Path to convert
    
    Returns:
    str: Unicode path string
    """

def augpath(path, suffix='', prefix='', ext=None, base=None, dpath=None, multidot=False):
    """
    Augment path with various components.
    
    Parameters:
    - path (str): Base path
    - suffix (str): Suffix to add to filename
    - prefix (str): Prefix to add to filename
    - ext (str): New extension (with or without dot)
    - base (str): New basename for file
    - dpath (str): New directory path
    - multidot (bool): Handle multiple extensions
    
    Returns:
    str: Augmented path
    """

def shrinkuser(path, home='~'):
    """
    Contract user home directory in path.
    
    Parameters:
    - path (str): Path to contract
    - home (str): Home directory representation
    
    Returns:
    str: Path with contracted home directory
    """

def expandpath(path):
    """
    Expand environment variables and user directory in path.
    
    Parameters:
    - path (str): Path to expand
    
    Returns:
    str: Expanded path
    """

class SpooledIOBase(IOBase):
    """Abstract base for spooled I/O implementations."""
    def __init__(self, max_size=5000000, dir=None): ...
    def rollover(self): ...
    @property
    def rolled(self): ...

class SpooledBytesIO(SpooledIOBase):
    """In-memory bytes I/O that spools to disk when large."""
    def write(self, s): ...
    def read(self, n=-1): ...
    def seek(self, pos, whence=0): ...
    def tell(self): ...

class SpooledStringIO(SpooledIOBase):
    """In-memory text I/O that spools to disk when large."""
    def write(self, s): ...
    def read(self, n=-1): ...
    def readline(self, length=None): ...

class MultiFileReader:
    """Read from multiple file objects as single stream."""
    def __init__(self, file_objects): ...
    def read(self, size=-1): ...
    def readline(self): ...
    def close(self): ...

def is_text_fileobj(fileobj):
    """
    Check if file object is in text mode.
    
    Parameters:
    - fileobj: File object to check
    
    Returns:
    bool: True if file object is in text mode
    """

class FilePerms:
    """File permissions representation and manipulation."""
    def __init__(self, perms): ...
    @property
    def user(self): ...
    @property
    def group(self): ...
    @property
    def other(self): ...
    def __str__(self): ...

class DummyFile:
    """File-like object that discards all writes."""
    def write(self, data): ...
    def flush(self): ...
    def close(self): ...

from boltons.fileutils import atomic_save, mkdir_p, augpath
from boltons.ioutils import SpooledBytesIO, MultiFileReader
from boltons.pathutils import shrinkuser, expandpath

# Atomic file writing
with atomic_save('/path/to/important.txt') as f:
    f.write('Critical data')
    # File is only written if no exceptions occur

# Create directories safely
mkdir_p('/path/to/nested/directories')

# Path manipulation
original = '/home/user/documents/file.txt'
backup = augpath(original, suffix='_backup', ext='.bak')
print(backup)  # '/home/user/documents/file_backup.bak'

# Contract and expand paths
short_path = shrinkuser('/home/user/file.txt')
print(short_path)  # '~/file.txt'
full_path = expandpath('~/file.txt')
print(full_path)   # '/home/user/file.txt'

# Spooled I/O for memory efficiency  
spooled = SpooledBytesIO(max_size=1024*1024)  # 1MB threshold
spooled.write(b'small data')  # Stays in memory
spooled.write(large_data)     # Spools to disk when threshold exceeded

# Read from multiple files as one stream
with open('file1.txt', 'rb') as f1, open('file2.txt', 'rb') as f2:
    multi_reader = MultiFileReader([f1, f2])
    combined_data = multi_reader.read()

# Constants
FULL_PERMS = 0o777      # Full read/write/execute permissions
RW_PERMS = 438          # Read/write permissions (octal 666)
READ_CHUNK_SIZE = 21333 # Default chunk size for reading operations