Add top-level copy/cp function

fsspec/__init__.py

@@ -10,7 +10,7 @@
 from . import caching
 from ._version import get_versions
 from .callbacks import Callback
-from .core import get_fs_token_paths, open, open_files, open_local
+from .core import copy, cp, get_fs_token_paths, open, open_files, open_local
 from .exceptions import FSTimeoutError
 from .mapping import FSMap, get_mapper
 from .registry import (
@@ -37,6 +37,8 @@
     "open",
     "open_files",
     "open_local",
+    "copy",
+    "cp",
     "registry",
     "caching",
     "Callback",

fsspec/core.py

@@ -468,6 +468,35 @@ def open_local(url, mode="rb", **storage_options):
     return paths
 
 
+def cp(filea, fileb: OpenFile, callback=None, **open_kwargs):
+    """Copy ``filea`` to ``fileb``.
+
+    Parameters
+    ----------
+    filea: str
+        The path to a local or remote file.
+    fileb: OpenFile
+        The target to write to. Must be in write mode.
+    callback:
+
+    open_kwargs: dict
+        Additional arguments passed to ``fsspec.open``
+        when opening ``filea``.
+    """
+    with open(filea, **open_kwargs) as a:
+        with fileb as b:
+            while True:
+                data = a.read(a.fs.blocksize)
+                if not data:
+                    break
+                b.write(data)
+
+
+def copy():
+    """Alias for `cp`"""
+    pass
+
+
 def get_compression(urlpath, compression):
     if compression == "infer":
         compression = infer_compression(urlpath)

fsspec/tests/test_api.py

@@ -187,6 +187,21 @@ def test_chained_fs():
     assert os.listdir(d2) == ["f1"]
 
 
+def test_cp():
+    d = tempfile.mkdtemp()
+    f1 = os.path.join(d, "f1")
+    f2 = os.path.join(d, "f2")
+    with open(f1, "wb") as f:
+        f.write(b"test")
+
+    target = fsspec.open(f2, mode="wb")
+    fsspec.cp(f1, target)
+    target.close()
+
+    with fsspec.open(f2) as f:
+        assert f.read() == b"test"
+
+
 @pytest.mark.xfail(reason="see issue #334", strict=True)
 def test_multilevel_chained_fs():
     """This test reproduces intake/filesystem_spec#334"""