from __future__ import annotations
import io
import logging
import os
import re
from glob import has_magic
from pathlib import Path
# for backwards compat, we export cache things from here too
from fsspec.caching import ( # noqa: F401
BaseCache,
BlockCache,
BytesCache,
MMapCache,
ReadAheadCache,
caches,
)
from fsspec.compression import compr
from fsspec.config import conf
from fsspec.registry import filesystem, get_filesystem_class
from fsspec.utils import (
_unstrip_protocol,
build_name_function,
infer_compression,
stringify_path,
)
logger = logging.getLogger("fsspec")
class OpenFile:
"""
File-like object to be used in a context
Can layer (buffered) text-mode and compression over any file-system, which
are typically binary-only.
These instances are safe to serialize, as the low-level file object
is not created until invoked using ``with``.
Parameters
----------
fs: FileSystem
The file system to use for opening the file. Should be a subclass or duck-type
with ``fsspec.spec.AbstractFileSystem``
path: str
Location to open
mode: str like 'rb', optional
Mode of the opened file
compression: str or None, optional
Compression to apply
encoding: str or None, optional
The encoding to use if opened in text mode.
errors: str or None, optional
How to handle encoding errors if opened in text mode.
newline: None or str
Passed to TextIOWrapper in text mode, how to handle line endings.
autoopen: bool
If True, calls open() immediately. Mostly used by pickle
pos: int
If given and autoopen is True, seek to this location immediately
"""
def __init__(
self,
fs,
path,
mode="rb",
compression=None,
encoding=None,
errors=None,
newline=None,
):
self.fs = fs
self.path = path
self.mode = mode
self.compression = get_compression(path, compression)
self.encoding = encoding
self.errors = errors
self.newline = newline
self.fobjects = []
def __reduce__(self):
return (
OpenFile,
(
self.fs,
self.path,
self.mode,
self.compression,
self.encoding,
self.errors,
self.newline,
),
)
def __repr__(self):
return f"<OpenFile '{self.path}'>"
def __enter__(self):
mode = self.mode.replace("t", "").replace("b", "") + "b"
try:
f = self.fs.open(self.path, mode=mode)
except FileNotFoundError as e:
if has_magic(self.path):
raise FileNotFoundError(
"%s not found. The URL contains glob characters: you maybe needed\n"
"to pass expand=True in fsspec.open() or the storage_options of \n"
"your library. You can also set the config value 'open_expand'\n"
"before import, or fsspec.core.DEFAULT_EXPAND at runtime, to True.",
self.path,
) from e
raise
self.fobjects = [f]
if self.compression is not None:
compress = compr[self.compression]
f = compress(f, mode=mode[0])
self.fobjects.append(f)
if "b" not in self.mode:
# assume, for example, that 'r' is equivalent to 'rt' as in builtin
f = PickleableTextIOWrapper(
f, encoding=self.encoding, errors=self.errors, newline=self.newline
)
self.fobjects.append(f)
return self.fobjects[-1]
def __exit__(self, *args):
self.close()
@property
def full_name(self):
return _unstrip_protocol(self.path, self.fs)
def open(self):
"""Materialise this as a real open file without context
The OpenFile object should be explicitly closed to avoid enclosed file
instances persisting. You must, therefore, keep a reference to the OpenFile
during the life of the file-like it generates.
"""
return self.__enter__()
def close(self):
"""Close all encapsulated file objects"""
for f in reversed(self.fobjects):
if "r" not in self.mode and not f.closed:
f.flush()
f.close()
self.fobjects.clear()
class OpenFiles(list):
"""List of OpenFile instances
Can be used in a single context, which opens and closes all of the
contained files. Normal list access to get the elements works as
normal.
A special case is made for caching filesystems - the files will
be down/uploaded together at the start or end of the context, and
this may happen concurrently, if the target filesystem supports it.
"""
def __init__(self, *args, mode="rb", fs=None):
self.mode = mode
self.fs = fs
self.files = []
super().__init__(*args)
def __enter__(self):
if self.fs is None:
raise ValueError("Context has already been used")
fs = self.fs
while True:
if hasattr(fs, "open_many"):
# check for concurrent cache download; or set up for upload
self.files = fs.open_many(self)
return self.files
if hasattr(fs, "fs") and fs.fs is not None:
fs = fs.fs
else:
break
return [s.__enter__() for s in self]
def __exit__(self, *args):
fs = self.fs
[s.__exit__(*args) for s in self]
if "r" not in self.mode:
while True:
if hasattr(fs, "open_many"):
# check for concurrent cache upload
fs.commit_many(self.files)
return
if hasattr(fs, "fs") and fs.fs is not None:
fs = fs.fs
else:
break
def __getitem__(self, item):
out = super().__getitem__(item)
if isinstance(item, slice):
return OpenFiles(out, mode=self.mode, fs=self.fs)
return out
def __repr__(self):
return f"<List of {len(self)} OpenFile instances>"
def open_files(
urlpath,
mode="rb",
compression=None,
encoding="utf8",
errors=None,
name_function=None,
num=1,
protocol=None,
newline=None,
auto_mkdir=True,
expand=True,
**kwargs,
):
"""Given a path or paths, return a list of ``OpenFile`` objects.
For writing, a str path must contain the "*" character, which will be filled
in by increasing numbers, e.g., "part*" -> "part1", "part2" if num=2.
For either reading or writing, can instead provide explicit list of paths.
Parameters
----------
urlpath: string or list
Absolute or relative filepath(s). Prefix with a protocol like ``s3://``
to read from alternative filesystems. To read from multiple files you
can pass a globstring or a list of paths, with the caveat that they
must all have the same protocol.
mode: 'rb', 'wt', etc.
compression: string or None
If given, open file using compression codec. Can either be a compression
name (a key in ``fsspec.compression.compr``) or "infer" to guess the
compression from the filename suffix.
encoding: str
For text mode only
errors: None or str
Passed to TextIOWrapper in text mode
name_function: function or None
if opening a set of files for writing, those files do not yet exist,
so we need to generate their names by formatting the urlpath for
each sequence number
num: int [1]
if writing mode, number of files we expect to create (passed to
name+function)
protocol: str or None
If given, overrides the protocol found in the URL.
newline: bytes or None
Used for line terminator in text mode. If None, uses system default;
if blank, uses no translation.
auto_mkdir: bool (True)
If in write mode, this will ensure the target directory exists before
writing, by calling ``fs.mkdirs(exist_ok=True)``.
expand: bool
**kwargs: dict
Extra options that make sense to a particular storage connection, e.g.
host, port, username, password, etc.
Examples
--------
>>> files = open_files('2015-*-*.csv') # doctest: +SKIP
>>> files = open_files(
... 's3://bucket/2015-*-*.csv.gz', compression='gzip'
... ) # doctest: +SKIP
Returns
-------
An ``OpenFiles`` instance, which is a list of ``OpenFile`` objects that can
be used as a single context
Notes
-----
For a full list of the available protocols and the implementations that
they map across to see the latest online documentation:
- For implementations built into ``fsspec`` see
https://filesystem-spec.readthedocs.io/en/latest/api.html#built-in-implementations
- For implementations in separate packages see
https://filesystem-spec.readthedocs.io/en/latest/api.html#other-known-implementations
"""
fs, fs_token, paths = get_fs_token_paths(
urlpath,
mode,
num=num,
name_function=name_function,
storage_options=kwargs,
protocol=protocol,
expand=expand,
)
if fs.protocol == "file":
fs.auto_mkdir = auto_mkdir
elif "r" not in mode and auto_mkdir:
parents = {fs._parent(path) for path in paths}
for parent in parents:
try:
fs.makedirs(parent, exist_ok=True)
except PermissionError:
pass
return OpenFiles(
[
OpenFile(
fs,
path,
mode=mode,
compression=compression,
encoding=encoding,
errors=errors,
newline=newline,
)
for path in paths
],
mode=mode,
fs=fs,
)
def _un_chain(path, kwargs):
x = re.compile(".*[^a-z]+.*") # test for non protocol-like single word
bits = (
[p if "://" in p or x.match(p) else p + "://" for p in path.split("::")]
if "::" in path
else [path]
)
# [[url, protocol, kwargs], ...]
out = []
previous_bit = None
kwargs = kwargs.copy()
for bit in reversed(bits):
protocol = kwargs.pop("protocol", None) or split_protocol(bit)[0] or "file"
cls = get_filesystem_class(protocol)
extra_kwargs = cls._get_kwargs_from_urls(bit)
kws = kwargs.pop(protocol, {})
if bit is bits[0]:
kws.update(kwargs)
kw = dict(**extra_kwargs, **kws)
bit = cls._strip_protocol(bit)
if (
protocol in {"blockcache", "filecache", "simplecache"}
and "target_protocol" not in kw
):
bit = previous_bit
out.append((bit, protocol, kw))
previous_bit = bit
out.reverse()
return out
def url_to_fs(url, **kwargs):
"""
Turn fully-qualified and potentially chained URL into filesystem instance
Parameters
----------
url : str
The fsspec-compatible URL
**kwargs: dict
Extra options that make sense to a particular storage connection, e.g.
host, port, username, password, etc.
Returns
-------
filesystem : FileSystem
The new filesystem discovered from ``url`` and created with
``**kwargs``.
urlpath : str
The file-systems-specific URL for ``url``.
"""
url = stringify_path(url)
# non-FS arguments that appear in fsspec.open()
# inspect could keep this in sync with open()'s signature
known_kwargs = {
"compression",
"encoding",
"errors",
"expand",
"mode",
"name_function",
"newline",
"num",
}
kwargs = {k: v for k, v in kwargs.items() if k not in known_kwargs}
chain = _un_chain(url, kwargs)
inkwargs = {}
# Reverse iterate the chain, creating a nested target_* structure
for i, ch in enumerate(reversed(chain)):
urls, protocol, kw = ch
if i == len(chain) - 1:
inkwargs = dict(**kw, **inkwargs)
continue
inkwargs["target_options"] = dict(**kw, **inkwargs)
inkwargs["target_protocol"] = protocol
inkwargs["fo"] = urls
urlpath, protocol, _ = chain[0]
fs = filesystem(protocol, **inkwargs)
return fs, urlpath
DEFAULT_EXPAND = conf.get("open_expand", False)
def open(
urlpath,
mode="rb",
compression=None,
encoding="utf8",
errors=None,
protocol=None,
newline=None,
expand=None,
**kwargs,
):
"""Given a path or paths, return one ``OpenFile`` object.
Parameters
----------
urlpath: string or list
Absolute or relative filepath. Prefix with a protocol like ``s3://``
to read from alternative filesystems. Should not include glob
character(s).
mode: 'rb', 'wt', etc.
compression: string or None
If given, open file using compression codec. Can either be a compression
name (a key in ``fsspec.compression.compr``) or "infer" to guess the
compression from the filename suffix.
encoding: str
For text mode only
errors: None or str
Passed to TextIOWrapper in text mode
protocol: str or None
If given, overrides the protocol found in the URL.
newline: bytes or None
Used for line terminator in text mode. If None, uses system default;
if blank, uses no translation.
expand: bool or Nonw
Whether to regard file paths containing special glob characters as needing
expansion (finding the first match) or absolute. Setting False allows using
paths which do embed such characters. If None (default), this argument
takes its value from the DEFAULT_EXPAND module variable, which takes
its initial value from the "open_expand" config value at startup, which will
be False if not set.
**kwargs: dict
Extra options that make sense to a particular storage connection, e.g.
host, port, username, password, etc.
Examples
--------
>>> openfile = open('2015-01-01.csv') # doctest: +SKIP
>>> openfile = open(
... 's3://bucket/2015-01-01.csv.gz', compression='gzip'
... ) # doctest: +SKIP
>>> with openfile as f:
... df = pd.read_csv(f) # doctest: +SKIP
...
Returns
-------
``OpenFile`` object.
Notes
-----
For a full list of the available protocols and the implementations that
they map across to see the latest online documentation:
- For implementations built into ``fsspec`` see
https://filesystem-spec.readthedocs.io/en/latest/api.html#built-in-implementations
- For implementations in separate packages see
https://filesystem-spec.readthedocs.io/en/latest/api.html#other-known-implementations
"""
expand = DEFAULT_EXPAND if expand is None else expand
out = open_files(
urlpath=[urlpath],
mode=mode,
compression=compression,
encoding=encoding,
errors=errors,
protocol=protocol,
newline=newline,
expand=expand,
**kwargs,
)
if not out:
raise FileNotFoundError(urlpath)
return out[0]
def open_local(
url: str | list[str] | Path | list[Path],
mode: str = "rb",
**storage_options: dict,
) -> str | list[str]:
"""Open file(s) which can be resolved to local
For files which either are local, or get downloaded upon open
(e.g., by file caching)
Parameters
----------
url: str or list(str)
mode: str
Must be read mode
storage_options:
passed on to FS for or used by open_files (e.g., compression)
"""
if "r" not in mode:
raise ValueError("Can only ensure local files when reading")
of = open_files(url, mode=mode, **storage_options)
if not getattr(of[0].fs, "local_file", False):
raise ValueError(
"open_local can only be used on a filesystem which"
" has attribute local_file=True"
)
with of as files:
paths = [f.name for f in files]
if (isinstance(url, str) and not has_magic(url)) or isinstance(url, Path):
return paths[0]
return paths
def get_compression(urlpath, compression):
if compression == "infer":
compression = infer_compression(urlpath)
if compression is not None and compression not in compr:
raise ValueError(f"Compression type {compression} not supported")
return compression
def split_protocol(urlpath):
"""Return protocol, path pair"""
urlpath = stringify_path(urlpath)
if "://" in urlpath:
protocol, path = urlpath.split("://", 1)
if len(protocol) > 1:
# excludes Windows paths
return protocol, path
if urlpath.startswith("data:"):
return urlpath.split(":", 1)
return None, urlpath
def strip_protocol(urlpath):
"""Return only path part of full URL, according to appropriate backend"""
protocol, _ = split_protocol(urlpath)
cls = get_filesystem_class(protocol)
return cls._strip_protocol(urlpath)
def expand_paths_if_needed(paths, mode, num, fs, name_function):
"""Expand paths if they have a ``*`` in them (write mode) or any of ``*?[]``
in them (read mode).
:param paths: list of paths
mode: str
Mode in which to open files.
num: int
If opening in writing mode, number of files we expect to create.
fs: filesystem object
name_function: callable
If opening in writing mode, this callable is used to generate path
names. Names are generated for each partition by
``urlpath.replace('*', name_function(partition_index))``.
:return: list of paths
"""
expanded_paths = []
paths = list(paths)
if "w" in mode: # read mode
if sum([1 for p in paths if "*" in p]) > 1:
raise ValueError(
"When writing data, only one filename mask can be specified."
)
num = max(num, len(paths))
for curr_path in paths:
if "*" in curr_path:
# expand using name_function
expanded_paths.extend(_expand_paths(curr_path, name_function, num))
else:
expanded_paths.append(curr_path)
# if we generated more paths that asked for, trim the list
if len(expanded_paths) > num:
expanded_paths = expanded_paths[:num]
else: # read mode
for curr_path in paths:
if has_magic(curr_path):
# expand using glob
expanded_paths.extend(fs.glob(curr_path))
else:
expanded_paths.append(curr_path)
return expanded_paths
def get_fs_token_paths(
urlpath,
mode="rb",
num=1,
name_function=None,
storage_options=None,
protocol=None,
expand=True,
):
"""Filesystem, deterministic token, and paths from a urlpath and options.
Parameters
----------
urlpath: string or iterable
Absolute or relative filepath, URL (may include protocols like
``s3://``), or globstring pointing to data.
mode: str, optional
Mode in which to open files.
num: int, optional
If opening in writing mode, number of files we expect to create.
name_function: callable, optional
If opening in writing mode, this callable is used to generate path
names. Names are generated for each partition by
``urlpath.replace('*', name_function(partition_index))``.
storage_options: dict, optional
Additional keywords to pass to the filesystem class.
protocol: str or None
To override the protocol specifier in the URL
expand: bool
Expand string paths for writing, assuming the path is a directory
"""
if isinstance(urlpath, (list, tuple, set)):
if not urlpath:
raise ValueError("empty urlpath sequence")
urlpath0 = stringify_path(next(iter(urlpath)))
else:
urlpath0 = stringify_path(urlpath)
storage_options = storage_options or {}
if protocol:
storage_options["protocol"] = protocol
chain = _un_chain(urlpath0, storage_options or {})
inkwargs = {}
# Reverse iterate the chain, creating a nested target_* structure
for i, ch in enumerate(reversed(chain)):
urls, nested_protocol, kw = ch
if i == len(chain) - 1:
inkwargs = dict(**kw, **inkwargs)
continue
inkwargs["target_options"] = dict(**kw, **inkwargs)
inkwargs["target_protocol"] = nested_protocol
inkwargs["fo"] = urls
paths, protocol, _ = chain[0]
fs = filesystem(protocol, **inkwargs)
if isinstance(urlpath, (list, tuple, set)):
pchains = [
_un_chain(stringify_path(u), storage_options or {})[0] for u in urlpath
]
if len({pc[1] for pc in pchains}) > 1:
raise ValueError("Protocol mismatch getting fs from %s", urlpath)
paths = [pc[0] for pc in pchains]
else:
paths = fs._strip_protocol(paths)
if isinstance(paths, (list, tuple, set)):
if expand:
paths = expand_paths_if_needed(paths, mode, num, fs, name_function)
elif not isinstance(paths, list):
paths = list(paths)
else:
if "w" in mode and expand:
paths = _expand_paths(paths, name_function, num)
elif "x" in mode and expand:
paths = _expand_paths(paths, name_function, num)
elif "*" in paths:
paths = [f for f in sorted(fs.glob(paths)) if not fs.isdir(f)]
else:
paths = [paths]
return fs, fs._fs_token, paths
def _expand_paths(path, name_function, num):
if isinstance(path, str):
if path.count("*") > 1:
raise ValueError("Output path spec must contain exactly one '*'.")
elif "*" not in path:
path = os.path.join(path, "*.part")
if name_function is None:
name_function = build_name_function(num - 1)
paths = [path.replace("*", name_function(i)) for i in range(num)]
if paths != sorted(paths):
logger.warning(
"In order to preserve order between partitions"
" paths created with ``name_function`` should "
"sort to partition order"
)
elif isinstance(path, (tuple, list)):
assert len(path) == num
paths = list(path)
else:
raise ValueError(
"Path should be either\n"
"1. A list of paths: ['foo.json', 'bar.json', ...]\n"
"2. A directory: 'foo/\n"
"3. A path with a '*' in it: 'foo.*.json'"
)
return paths
class PickleableTextIOWrapper(io.TextIOWrapper):
"""TextIOWrapper cannot be pickled. This solves it.
Requires that ``buffer`` be pickleable, which all instances of
AbstractBufferedFile are.
"""
def __init__(
self,
buffer,
encoding=None,
errors=None,
newline=None,
line_buffering=False,
write_through=False,
):
self.args = buffer, encoding, errors, newline, line_buffering, write_through
super().__init__(*self.args)
def __reduce__(self):
return PickleableTextIOWrapper, self.args