Copy file with pathlib in Python

Question

I try to copy a file with pathlib

import pathlib import shutil  my_file=pathlib.Path('/etc/hosts') to_file=pathlib.Path('/tmp/foo') shutil.copy(my_file, to_file) 

I get this exception:

/home/foo_egs_d/bin/python /home/foo_egs_d/src/test-pathlib-copy.py Traceback (most recent call last):   File "/home/foo_egs_d/src/test-pathlib-copy.py", line 6, in <module>     shutil.copy(my_file, to_file)   File "/usr/lib/python2.7/shutil.py", line 117, in copy     if os.path.isdir(dst):   File "/home/foo_egs_d/lib/python2.7/genericpath.py", line 41, in isdir     st = os.stat(s) TypeError: coercing to Unicode: need string or buffer, PosixPath found  Process finished with exit code 

... how to copy file with pathlib in Python 2.7?

Answer 1

To use shutil.copy:

import pathlib import shutil  my_file = pathlib.Path('/etc/hosts') to_file = pathlib.Path('/tmp/foo')  shutil.copy(str(my_file), str(to_file))  # For Python <= 3.7. shutil.copy(my_file, to_file)  # For Python 3.8+. 

The problem is pathlib.Path create a PosixPath object if you're using Unix/Linux, WindowsPath if you're using Microsoft Windows.

With older versions of Python, shutil.copy requires a string as its arguments. For them, use the str function here.

Answer 2

The cause for shutil.copy() not working is that you are not using the latest Python, Python 3.6 shutil.copy() can handle Path objects (or subclasses thereof). That for older versions of Python this throws an error is because those implementations of shutil expect string arguments for copy, and not pathlib.Path type arguments.

What you actually want to be able to write is:

my_file.copy(to_file) 

You can subclass Path to include such a method, and adapt the creation of my_file. I find it easier to just graft/monkey-patch/duck-punch it on the existing pathlib.Path

from pathlib import Path   def _copy(self, target):     import shutil     assert self.is_file()     shutil.copy(str(self), str(target))  # str() only there for Python < (3, 6)  Path.copy = _copy 

You can put this code anywhere you like, as long as it gets executed before calling the .copy method on any of the Path instances. The argument to .copy() can be a file or a directory.