1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343
|
Copying files and directories
=============================
This documents the expected behavior of the ``fsspec`` file and directory copying functions.
There are three functions of interest here: :meth:`~fsspec.spec.AbstractFileSystem.copy`,
:meth:`~fsspec.spec.AbstractFileSystem.get` and :meth:`~fsspec.spec.AbstractFileSystem.put`.
Each of these copies files and/or directories from a ``source`` to a ``target`` location.
If we refer to our filesystem of interest, derived from :class:`~fsspec.spec.AbstractFileSystem`,
as the remote filesystem (even though it may be local) then the difference between the three
functions is:
- :meth:`~fsspec.spec.AbstractFileSystem.copy` copies from a remote ``source`` to a remote ``target``
- :meth:`~fsspec.spec.AbstractFileSystem.get` copies from a remote ``source`` to a local ``target``
- :meth:`~fsspec.spec.AbstractFileSystem.put` copies from a local ``source`` to a remote ``target``
The ``source`` and ``target`` are the first two arguments passed to these functions, and each
consists of one or more files, directories and/or ``glob`` (wildcard) patterns.
The behavior of the ``fsspec`` copy functions is intended to be the same as that obtained using
POSIX command line ``cp`` but ``fsspec`` functions have extra functionality because:
- They support more than one ``target`` whereas command line ``cp`` is restricted to one.
- They can create new directories, either automatically or via the ``auto_mkdir=True`` keyword
argument, whereas command line ``cp`` only does this as part of a recursive copy.
Expected behavior
-----------------
There follows a comprehensive list of the expected behavior of the ``fsspec`` copying functions
that also forms the basis of a set of tests that all classes that derive from
:class:`~fsspec.spec.AbstractFileSystem` can be tested against to check that they conform.
For all scenarios the ``source`` filesystem contains the following directories and files::
📁 source
├── 📄 file1
├── 📄 file2
└── 📁 subdir
├── 📄 subfile1
├── 📄 subfile2
└── 📁 nesteddir
└── 📄 nestedfile
and before each scenario the ``target`` directory exists and is empty unless otherwise noted::
📁 target
All example code uses :meth:`~fsspec.spec.AbstractFileSystem.cp` which is an alias of
:meth:`~fsspec.spec.AbstractFileSystem.copy`; equivalent behavior is expected by
:meth:`~fsspec.spec.AbstractFileSystem.get` and :meth:`~fsspec.spec.AbstractFileSystem.put`.
Forward slashes are used for directory separators throughout.
1. Single source to single target
---------------------------------
.. dropdown:: 1a. File to existing directory
.. code-block:: python
cp("source/subdir/subfile1", "target/")
results in::
📁 target
└── 📄 subfile1
The trailing slash on ``"target/"`` is optional but recommended as it explicitly indicates that
the target is a directory.
.. dropdown:: 1b. File to new directory
.. code-block:: python
cp("source/subdir/subfile1", "target/newdir/")
results in::
📁 target
└── 📁 newdir
└── 📄 subfile1
This fails if the ``target`` file system is not capable of creating the directory, for example
if it is write-only or if ``auto_mkdir=False``. There is no command line equivalent of this
scenario without an explicit ``mkdir`` to create the new directory.
The trailing slash is required on the new directory otherwise it is interpreted as a filename
which is a different scenario (1d. File to file in new directory).
.. dropdown:: 1c. File to file in existing directory
.. code-block:: python
cp("source/subdir/subfile1", "target/newfile")
results in::
📁 target
└── 📄 newfile
The target cannot have a trailing slash as ``"newfile/"`` is interpreted as a new directory
which is a different scenario (1b. File to new directory).
.. dropdown:: 1d. File to file in new directory
.. code-block:: python
cp("source/subdir/subfile1", "target/newdir/newfile")
creates the new directory and copies the file into it::
📁 target
└── 📁 newdir
└── 📄 newfile
This fails if the ``target`` file system is not capable of creating the directory, for example
if it is write-only or if ``auto_mkdir=False``. There is no command line equivalent of this
scenario without an explicit ``mkdir`` to create the new directory.
If there is a trailing slash on the target ``target/newdir/newfile/`` then it is interpreted as
a new directory which is a different scenario (1b. File to new directory).
.. dropdown:: 1e. Directory to existing directory
.. code-block:: python
cp("source/subdir/", "target/", recursive=True)
results in::
📁 target
├── 📄 subfile1
└── 📄 subfile2
└── 📁 nesteddir
└── 📄 nestedfile
The ``recursive=True`` keyword argument is required otherwise the call does nothing. The depth
of recursion can be controlled using the ``maxdepth`` keyword argument, for example:
.. code-block:: python
cp("source/subdir/", "target/", recursive=True, maxdepth=1)
results in::
📁 target
├── 📄 subfile1
└── 📄 subfile2
The trailing slash on ``"target/"`` is optional but recommended as it explicitly indicates that
the target is a directory.
If the trailing slash is omitted from ``"source/subdir"`` then the ``subdir`` is also copied,
not just its contents:
.. code-block:: python
cp("source/subdir", "target/", recursive=True)
results in::
📁 target
└── 📁 subdir
├── 📄 subfile1
└── 📄 subfile2
└── 📁 nesteddir
└── 📄 nestedfile
Again the depth of recursion can be controlled using the ``maxdepth`` keyword argument, for
example:
.. code-block:: python
cp("source/subdir", "target/", recursive=True, maxdepth=1)
results in::
📁 target
└── 📁 subdir
├── 📄 subfile1
└── 📄 subfile2
.. dropdown:: 1f. Directory to new directory
.. code-block:: python
cp("source/subdir/", "target/newdir/", recursive=True)
results in::
📁 target
└── 📁 newdir
├── 📄 subfile1
└── 📄 subfile2
└── 📁 nesteddir
└── 📄 nestedfile
Trailing slashes on both ``source`` and ``target`` are optional and do not affect the result.
They are recommended to explicitly indicate both are directories.
The ``recursive=True`` keyword argument is required otherwise the call does nothing. The depth
of recursion can be controlled using the ``maxdepth`` keyword argument, for example:
.. code-block:: python
cp("source/subdir/", "target/newdir/", recursive=True, maxdepth=1)
results in::
📁 target
└── 📁 newdir
├── 📄 subfile1
└── 📄 subfile2
.. dropdown:: 1g. Glob to existing directory
Nonrecursive
.. code-block:: python
cp("source/subdir/*", "target/")
copies files from the top-level directory only and results in::
📁 target
├── 📄 subfile1
└── 📄 subfile2
Recursive
.. code-block:: python
cp("source/subdir/*", "target/", recursive=True)
results in::
📁 target
├── 📄 subfile1
└── 📄 subfile2
└── 📁 nesteddir
└── 📄 nestedfile
The trailing slash on ``"target/"`` is optional but recommended as it explicitly indicates that
the target is a directory.
The depth of recursion can be controlled by the ``maxdepth`` keyword argument, for example:
.. code-block:: python
cp("source/subdir/*", "target/", recursive=True, maxdepth=1)
results in::
📁 target
├── 📄 subfile1
└── 📄 subfile2
.. dropdown:: 1h. Glob to new directory
Nonrecursive
.. code-block:: python
cp("source/subdir/*", "target/newdir/")
copies files from the top-level directory only and results in::
📁 target
└── 📁 newdir
├── 📄 subfile1
└── 📄 subfile2
Recursive
.. code-block:: python
cp("source/subdir/*", "target/newdir/", recursive=True)
results in::
📁 target
└── 📁 newdir
├── 📄 subfile1
└── 📄 subfile2
└── 📁 nesteddir
└── 📄 nestedfile
The trailing slash on the ``target`` is optional but recommended as it explicitly indicates that
it is a directory.
The depth of recursion can be controlled by the ``maxdepth`` keyword argument, for example:
.. code-block:: python
cp("source/subdir/*", "target/newdir/", recursive=True, maxdepth=1)
results in::
📁 target
└── 📁 newdir
├── 📄 subfile1
└── 📄 subfile2
These calls fail if the ``target`` file system is not capable of creating the directory, for
example if it is write-only or if ``auto_mkdir=False``. There is no command line equivalent of
this scenario without an explicit ``mkdir`` to create the new directory.
2. Multiple source to single target
-----------------------------------
.. dropdown:: 2a. List of files to existing directory
.. code-block:: python
cp(["source/file1", "source/file2", "source/subdir/subfile1"], "target/")
results in::
📁 target
├── 📄 file1
├── 📄 file2
└── 📄 subfile1
All of the files are copied to the target directory regardless of their relative paths in the
source filesystem. The trailing slash on the ``target`` is optional but recommended as it
explicitly indicates that it is a directory.
.. dropdown:: 2b. List of files to new directory
.. code-block:: python
cp(["source/file1", "source/file2", "source/subdir/subfile1"], "target/newdir/")
results in::
📁 target
└── 📁 newdir
├── 📄 file1
├── 📄 file2
└── 📄 subfile1
All of the files are copied to the target directory regardless of their relative paths in the
source filesystem.
The trailing slash is required on the new directory otherwise it is interpreted as a filename
rather than a directory.
|