from __future__ import absolute_import, division, print_function
import io
import logging
import os
import re
from glob import has_magic
# for backwards compat, we export cache things from here too
from .caching import ( # noqa: F401
BaseCache,
BlockCache,
BytesCache,
MMapCache,
ReadAheadCache,
caches,
)
from .compression import compr
from .registry import filesystem, get_filesystem_class
from .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 "<OpenFile '{}'>".format(self.path)
def __enter__(self):
mode = self.mode.replace("t", "").replace("b", "") + "b"
f = self.fs.open(self.path, mode=mode)
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 "<List of %s OpenFile instances>" % len(self)
def open_files(
urlpath,
mode="rb",
compression=None,
encoding="utf8",
errors=None,
name_function=None,
num=1,
protocol=None,
newline=None,
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.
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,
)
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 = list(reversed(out))
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``.
"""
# 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
def open(
urlpath,
mode="rb",
compression=None,
encoding="utf8",
errors=None,
protocol=None,
newline=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.
**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
"""
out = open_files(
urlpath=[urlpath],
mode=mode,
compression=compression,
encoding=encoding,
errors=errors,
protocol=protocol,
newline=newline,
expand=False,
**kwargs,
)
if not out:
raise FileNotFoundError(urlpath)
return out[0]
def open_local(url, mode="rb", **storage_options):
"""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):
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("Compression type %s not supported" % compression)
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
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(list(urlpath)[0])
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)):
paths = expand_paths_if_needed(paths, mode, num, fs, name_function)
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