การใช้งาน Python Pathlib: เชี่ยวชาญการจัดการพาธและการดำเนินการระบบไฟล์

            import os

base_dir = '/users/john/documents'
config_file = 'settings.ini'
full_path = os.path.join(base_dir, 'config', config_file)

if os.path.exists(full_path):
    print(f\"Configuration file found at: {full_path}\")
else:
    print(f\"Configuration file not found at: {full_path}\")

            

              
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            from pathlib import Path

# Creating a Path object for the current directory
current_directory = Path('.')
print(f\"Current directory: {current_directory}\")

# Creating a Path object for a specific file
config_file_path = Path('/etc/myapp/settings.json')
print(f\"Config file path: {config_file_path}\")

# Using a relative path
relative_data_path = Path('data/raw/input.csv')
print(f\"Relative data path: {relative_data_path}\")

# Creating a path with multiple components using the / operator
# This is where the object-oriented nature shines!
project_root = Path('/home/user/my_project')
src_dir = project_root / 'src'
main_file = src_dir / 'main.py'

print(f\"Project root: {project_root}\")
print(f\"Source directory: {src_dir}\")
print(f\"Main Python file: {main_file}\")

            

              
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            from pathlib import Path

log_file = Path('/var/log/system/app.log')

print(f\"File name: {log_file.name}\")          # Output: app.log
print(f\"File stem: {log_file.stem}\")          # Output: app
print(f\"File suffix: {log_file.suffix}\")        # Output: .log
print(f\"Parent directory: {log_file.parent}\")    # Output: /var/log/system
print(f\"All parent directories: {list(log_file.parents)}\") # Output: [/var/log/system, /var/log, /var]
print(f\"Path parts: {log_file.parts}\")        # Output: ('/', 'var', 'log', 'system', 'app.log')

            

              
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            from pathlib import Path

# Assuming 'data' is a symlink to '/mnt/external_drive/datasets'
# And '.' represents the current directory
relative_path = Path('data/../logs/latest.log')

absolute_path = relative_path.resolve()
print(f\"Resolved path: {absolute_path}\")
# Example output (depending on your OS and setup):
# Resolved path: /home/user/my_project/logs/latest.log

            

              
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            from pathlib import Path

original_file = Path('/home/user/reports/monthly_sales.csv')

# Change the filename
renamed_file = original_file.with_name('quarterly_sales.csv')
print(f\"Renamed file: {renamed_file}\")
# Output: /home/user/reports/quarterly_sales.csv

# Change the suffix
xml_file = original_file.with_suffix('.xml')
print(f\"XML version: {xml_file}\")
# Output: /home/user/reports/monthly_sales.xml

# Combine operations
new_report_path = original_file.parent / 'archive' / original_file.with_suffix('.zip').name
print(f\"New archive path: {new_report_path}\")
# Output: /home/user/reports/archive/monthly_sales.zip

            

              
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            from pathlib import Path

my_file = Path('data/input.txt')
my_dir = Path('output')

# Create dummy file and directory for demonstration
my_file.parent.mkdir(parents=True, exist_ok=True) # Ensure parent dir exists
my_file.touch(exist_ok=True) # Create the file
my_dir.mkdir(exist_ok=True) # Create the directory

print(f\"Does '{my_file}' exist? {my_file.exists()}\")     # True
print(f\"Is '{my_file}' a file? {my_file.is_file()}\")   # True
print(f\"Is '{my_file}' a directory? {my_file.is_dir()}\") # False

print(f\"Does '{my_dir}' exist? {my_dir.exists()}\")     # True
print(f\"Is '{my_dir}' a file? {my_dir.is_file()}\")   # False
print(f\"Is '{my_dir}' a directory? {my_dir.is_dir()}\") # True

# Clean up dummy entries
my_file.unlink() # Deletes the file
my_dir.rmdir()   # Deletes the empty directory
my_file.parent.rmdir() # Deletes the parent directory if empty

            

              
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            from pathlib import Path

# Create a new directory
new_folder = Path('reports/monthly')
new_folder.mkdir(parents=True, exist_ok=True)
print(f\"Created directory: {new_folder}\")

# Create a new file
output_file = new_folder / 'summary.txt'
output_file.touch(exist_ok=True)
print(f\"Created file: {output_file}\")

# Write some content to the file (see reading/writing section)
output_file.write_text(\"This is a summary report.\n\")

# Delete the file
output_file.unlink()
print(f\"Deleted file: {output_file}\")

# Delete the directory (must be empty)
new_folder.rmdir()
print(f\"Deleted directory: {new_folder}\")

            

              
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            from pathlib import Path

# Writing text to a file
my_document = Path('documents/notes.txt')
my_document.parent.mkdir(parents=True, exist_ok=True)

content_to_write = \"First line of notes.\nSecond line.\n\" 
bytes_written = my_document.write_text(content_to_write, encoding='utf-8')
print(f\"Wrote {bytes_written} bytes to {my_document}\")

# Reading text from a file
read_content = my_document.read_text(encoding='utf-8')
print(f\"Content read from {my_document}:\")
print(read_content)

# Reading bytes (useful for binary files like images)
image_path = Path('images/logo.png')
# image_path.parent.mkdir(parents=True, exist_ok=True)
# For demonstration, let's create a dummy byte file
dummy_bytes = b'\\x89PNG\\r\\n\\x1a\\n\\x00\\x00\\x00\\rIHDR\\x00\\x00\\x00\\x01\\x00\\x00\\x00\\x01\\x08\\x06\\x00\\x00\\x00\\x1f\\x15\\xc4\\x89\\x00\\x00\\x00\\x0aIDATx\\x9cc\\xfc\\xff\\xff?\\x03\\x00\\x08\\xfc\\x02\\xfe\\xa7\\xcd\\xd2 \\x00\\x00\\x00IEND\\xaeB`\\x82'
image_path.write_bytes(dummy_bytes)

file_bytes = image_path.read_bytes()
print(f\"Read {len(file_bytes)} bytes from {image_path}\")

# Clean up dummy files
my_document.unlink()
image_path.unlink()
my_document.parent.rmdir()
# image_path.parent.rmdir() # Only if empty

            

              
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            from pathlib import Path

large_file = Path('data/large_log.txt')
large_file.parent.mkdir(parents=True, exist_ok=True)
large_file.write_text(\"Line 1\nLine 2\nLine 3\n\")

print(f\"Reading '{large_file}' line by line:\")
with large_file.open('r', encoding='utf-8') as f:
    for line in f:
        print(f\"  - {line.strip()}\")

# Clean up
large_file.unlink()
large_file.parent.rmdir()

            

              
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            from pathlib import Path

# Create a dummy directory structure for demonstration
base_dir = Path('project_files')
(base_dir / 'src').mkdir(parents=True, exist_ok=True)
(base_dir / 'docs').mkdir(parents=True, exist_ok=True)
(base_dir / 'src' / 'main.py').touch()
(base_dir / 'src' / 'utils.py').touch()
(base_dir / 'docs' / 'README.md').touch()
(base_dir / '.gitignore').touch()

print(f\"Contents of '{base_dir}':\")
for item in base_dir.iterdir():
    print(f\"- {item} (Type: {'Directory' if item.is_dir() else 'File'})\")

# Clean up dummy structure
import shutil
shutil.rmtree(base_dir) # Recursive removal

            

              
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            from pathlib import Path

# Recreate dummy structure
base_dir = Path('project_files')
(base_dir / 'src').mkdir(parents=True, exist_ok=True)
(base_dir / 'docs').mkdir(parents=True, exist_ok=True)
(base_dir / 'src' / 'main.py').touch()
(base_dir / 'src' / 'utils.py').touch()
(base_dir / 'docs' / 'README.md').touch()
(base_dir / '.gitignore').touch()
(base_dir / 'data' / 'raw' / 'input1.csv').touch()
(base_dir / 'data' / 'processed' / 'output1.csv').touch()

print(f\"All Python files in '{base_dir}' and subdirectories:\")
for py_file in base_dir.rglob('*.py'):
    print(f\"- {py_file}\")

print(f\"All .csv files in '{base_dir}/data' and subdirectories:\")
csv_files = (base_dir / 'data').rglob('*.csv')
for csv_file in csv_files:
    print(f\"- {csv_file}\")

print(f\"Files starting with 'main' in '{base_dir}/src':\")
main_files = (base_dir / 'src').glob('main*')
for mf in main_files:
    print(f\"- {mf}\")

# Clean up
import shutil
shutil.rmtree(base_dir)

            

              
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            from pathlib import Path

# Setup source files and directories
source_dir = Path('source_folder')
source_file = source_dir / 'document.txt'
source_dir.mkdir(exist_ok=True)
source_file.write_text('Content for document.')

# Destination
 dest_dir = Path('destination_folder')
 dest_dir.mkdir(exist_ok=True)

# --- Renaming/Moving a file ---
new_file_name = source_dir / 'renamed_document.txt'
source_file.rename(new_file_name)
print(f\"File renamed to: {new_file_name}\")
print(f\"Original file exists: {source_file.exists()}\") # False

# --- Moving a file to another directory ---
moved_file = dest_dir / new_file_name.name
new_file_name.rename(moved_file)
print(f\"File moved to: {moved_file}\")
print(f\"Original location exists: {new_file_name.exists()}\") # False

# --- Copying a file (Python 3.8+) ---
# If using older Python, you'd typically use shutil.copy2
# For demonstration, assume Python 3.8+
# Ensure source_file is recreated for copying
source_file.parent.mkdir(parents=True, exist_ok=True)
source_file.write_text('Content for document.')

copy_of_source = source_dir / 'copy_of_document.txt'
source_file.copy(copy_of_source)
print(f\"Copied file to: {copy_of_source}\")
print(f\"Original file still exists: {source_file.exists()}\") # True

# --- Copying a directory (Python 3.8+) ---
# For directories, you'd typically use shutil.copytree
# For demonstration, assume Python 3.8+
# Let's recreate source_dir with a subdirectory
source_dir.mkdir(parents=True, exist_ok=True)
(source_dir / 'subdir').mkdir(exist_ok=True)
(source_dir / 'subdir' / 'nested.txt').touch()

copy_of_source_dir = dest_dir / 'copied_source_folder'
# Note: Path.copy for directories requires the target to be the name of the new directory
source_dir.copy(copy_of_source_dir)
print(f\"Copied directory to: {copy_of_source_dir}\")
print(f\"Original directory exists: {source_dir.exists()}\") # True

# Clean up
import shutil
shutil.rmtree('source_folder')
shutil.rmtree('destination_folder')

            

              
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            from pathlib import Path
import stat # For permission flags

# Create a dummy file
permission_file = Path('temp_perms.txt')
permission_file.touch()

# Get current permissions
file_stat = permission_file.stat()
print(f\"Initial permissions: {oct(file_stat.st_mode)[-3:]}\") # e.g., '644'

# Change permissions (e.g., make it readable by owner only)
# owner read, owner write, no execute
new_mode = stat.S_IRUSR | stat.S_IWUSR
permission_file.chmod(new_mode)

file_stat_after = permission_file.stat()
print(f\"Updated permissions: {oct(file_stat_after.st_mode)[-3:]}\")

# Clean up
permission_file.unlink()

            

              
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            from pathlib import Path

# Get the user's home directory, regardless of OS
home_dir = Path.home()
print(f\"User's home directory: {home_dir}\")

# Construct a path to a user-specific configuration file
config_path = home_dir / '.myapp' / 'config.yml'
print(f\"Configuration file path: {config_path}\")

            

              
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