pathlib — 像操作对象一样操作文件系统路径

建立路径

# pathlib_operator.py
import pathlib

usr = pathlib.PurePosixPath('/usr')
print(usr)

usr_local = usr / 'local'
print(usr_local)

usr_share = usr / pathlib.PurePosixPath('share')
print(usr_share)

root = usr / '..'
print(root)

etc = root / '/etc/'
print(etc)

# pathlib_resolve.py
import pathlib

usr_local = pathlib.Path('/usr/local')
share = usr_local / '..' / 'share'
print(share.resolve())

# pathlib_joinpath.py
import pathlib

root = pathlib.PurePosixPath('/')
subdirs = ['usr', 'local']
usr_local = root.joinpath(*subdirs)
print(usr_local)

# pathlib_from_existing.py
import pathlib

ind = pathlib.PurePosixPath('source/pathlib/index.rst')
print(ind)

py = ind.with_name('pathlib_from_existing.py')
print(py)

pyc = py.with_suffix('.pyc')
print(pyc)

解析路径

# pathlib_parts.py
import pathlib

p = pathlib.PurePosixPath('/usr/local')
print(p.parts)

# pathlib_parents.py
import pathlib

p = pathlib.PurePosixPath('/usr/local/lib')

print('parent: {}'.format(p.parent))

print('\nhierarchy:')
for up in p.parents:
    print(up)

# pathlib_name.py
import pathlib

p = pathlib.PurePosixPath('./source/pathlib/pathlib_name.py')
print('path  : {}'.format(p))
print('name  : {}'.format(p.name))
print('suffix: {}'.format(p.suffix))
print('stem  : {}'.format(p.stem))

创建具体的路径

# pathlib_convenience.py
import pathlib

home = pathlib.Path.home()
print('home: ', home)

cwd = pathlib.Path.cwd()
print('cwd : ', cwd)

目录内容

# pathlib_iterdir.py
import pathlib

p = pathlib.Path('.')

for f in p.iterdir():
    print(f)

# pathlib_glob.py
import pathlib

p = pathlib.Path('..')

for f in p.glob('*.rst'):
    print(f)

# pathlib_rglob.py
import pathlib

p = pathlib.Path('..')

for f in p.rglob('pathlib_*.py'):
    print(f)

读写文件

# pathlib_read_write.py
import pathlib

f = pathlib.Path('example.txt')

f.write_bytes('This is the content'.encode('utf-8'))

with f.open('r', encoding='utf-8') as handle:
    print('read from open(): {!r}'.format(handle.read()))

print('read_text(): {!r}'.format(f.read_text('utf-8')))

操纵目录和符号链接

# pathlib_mkdir.py
import pathlib

p = pathlib.Path('example_dir')

print('Creating {}'.format(p))
p.mkdir()

# pathlib_symlink_to.py
import pathlib

p = pathlib.Path('example_link')

p.symlink_to('index.rst')

print(p)
print(p.resolve().name)

文件类型

# pathlib_types.py
import itertools
import os
import pathlib

root = pathlib.Path('test_files')

# Clean up from previous runs.
if root.exists():
    for f in root.iterdir():
        f.unlink()
else:
    root.mkdir()

# Create test files
(root / 'file').write_text(
    'This is a regular file', encoding='utf-8')
(root / 'symlink').symlink_to('file')
os.mkfifo(str(root / 'fifo'))

# Check the file types
to_scan = itertools.chain(
    root.iterdir(),
    [pathlib.Path('/dev/disk0'),
     pathlib.Path('/dev/console')],
)
hfmt = '{:18s}' + ('  {:>5}' * 6)
print(hfmt.format('Name', 'File', 'Dir', 'Link', 'FIFO', 'Block',
                  'Character'))
print()

fmt = '{:20s}  ' + ('{!r:>5}  ' * 6)
for f in to_scan:
    print(fmt.format(
        str(f),
        f.is_file(),
        f.is_dir(),
        f.is_symlink(),
        f.is_fifo(),
        f.is_block_device(),
        f.is_char_device(),
    ))

文件属性

# pathlib_stat.py
import pathlib
import sys
import time

if len(sys.argv) == 1:
    filename = __file__
else:
    filename = sys.argv[1]

p = pathlib.Path(filename)
stat_info = p.stat()

print('{}:'.format(filename))
print('  Size:', stat_info.st_size)
print('  Permissions:', oct(stat_info.st_mode))
print('  Owner:', stat_info.st_uid)
print('  Device:', stat_info.st_dev)
print('  Created      :', time.ctime(stat_info.st_ctime))
print('  Last modified:', time.ctime(stat_info.st_mtime))
print('  Last accessed:', time.ctime(stat_info.st_atime))

# pathlib_ownership.py
import pathlib

p = pathlib.Path(__file__)

print('{} is owned by {}/{}'.format(p, p.owner(), p.group()))

# pathlib_touch.py
import pathlib
import time

p = pathlib.Path('touched')
if p.exists():
    print('already exists')
else:
    print('creating new')

p.touch()
start = p.stat()

time.sleep(1)

p.touch()
end = p.stat()

print('Start:', time.ctime(start.st_mtime))
print('End  :', time.ctime(end.st_mtime))

权限

# pathlib_chmod.py
import os
import pathlib
import stat

# Create a fresh test file.
f = pathlib.Path('pathlib_chmod_example.txt')
if f.exists():
    f.unlink()
f.write_text('contents')

# Determine what permissions are already set using stat.
existing_permissions = stat.S_IMODE(f.stat().st_mode)
print('Before: {:o}'.format(existing_permissions))

# Decide which way to toggle them.
if not (existing_permissions & os.X_OK):
    print('Adding execute permission')
    new_permissions = existing_permissions | stat.S_IXUSR
else:
    print('Removing execute permission')
    # use xor to remove the user execute permission
    new_permissions = existing_permissions ^ stat.S_IXUSR

# Make the change and show the new value.
f.chmod(new_permissions)
after_permissions = stat.S_IMODE(f.stat().st_mode)
print('After: {:o}'.format(after_permissions))

删除

# pathlib_rmdir.py
import pathlib

p = pathlib.Path('example_dir')

print('Removing {}'.format(p))
p.rmdir()

# pathlib_unlink.py
import pathlib

p = pathlib.Path('touched')

p.touch()

print('exists before removing:', p.exists())

p.unlink()

print('exists after removing:', p.exists())