Python Pathlib Usage: Mastering Path Manipulation and File System Operations

            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\nIDATx\x9cc\xfc\xff\xff?\x03\x00\x08\xfc\x02\xfe\xa7\xcd\xd2\x00\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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