pathlib Path `write_text` in append mode

Not really, as you can see in the pathlib module exist 2 types of path classes:

• pure path classes {PurePath, PurePosixPath, PureWindowsPath}
• concrete path classes {Path, PosixPath, WindowsPath}.

Parameters of theses classes constructors will be just *pathsegments.

And if you look at the available read/write methods (read_text/read_bytes and write_text/write_bytes) you'll also see mode won't be available neither

So, as you've already discovered, the only way you can use mode with these pathlib classes is by using open method, ie:

with my_path.open("a") as f:
    f.write("...")

This is by design and that way the pathlib classes have become really "clean". Also, the above snippet is already canonical so it can't be simplified any further. You could use open method outside the context manager though:

f = my_path.open("a")
f.write("...")

The pathlib methods Path().write_text() and Path().write_bytes() close the file connection on exit.

from pathlib import Path

Path('file.txt').write_text('my text')
Path('file1.txt').write_bytes(b'my text')

Using append mode i.e open('a', ...) will instanciate a TextIOWrapper which is also closed by write_text / write_bytes on exit.

f = Path('file.txt')
f.open("a")
f.write_text('my text')
# or
f.write_bytes(b'my text')

Otherwise must close it manually

f = Path('file1.txt').open('a')
f.write('my text')
f.close()

but can be this way:

fp = Path('test.txt').open('a')
<_io.TextIOWrapper name='test.txt' mode='a' encoding='UTF-8'>
fp.write('my text')

fq = Path('test1.txt').open('ab', encoding='iso8859-1')
<_io.TextIOWrapper name='test1.txt' mode='a' encoding='iso8859-1'>
fq.write(b'my text')