This is quick-start documentation to help people get familiar with the layout and functioning of
Instantiate a file-system¶
fsspec provides an abstract file-system interface as a base class, to be used by other filesystems.
A file-system instance is an object for manipulating files on some
remote store, local files, files within some wrapper, or anything else that is capable of producing
Some concrete implementations are bundled with
fsspec and others can be installed separately. They
can be instantiated directly, or the registry can be used to find them.
from fsspec.implementations.local import LocalFileSystem fs = LocalFileSystem()
Look-up via registry:
import fsspec fs = fsspec.filesystem('file')
import fsspec fs = fsspec.filesystem('ftp', host=host, port=port, username=user, password=pw)
Use a file-system¶
File-system instances offer a large number of methods for getting information about and manipulating files
for the given back-end. Although some specific implementations may not offer all features (e.g.,
is read-only), generally all normal operations, such as
rm, should be expected to work (see the
Note that this quick-start will prefer posix-style naming, but
many common operations are aliased:
copy() are identical, for instance.
Functionality is generally chosen to be as close to the builtin
os module’s working for things like
glob as possible. The following block of operations should seem very familiar.
fs.mkdir("/remote/output") fs.touch("/remote/output/success") # creates empty file assert fs.exists("/remote/output/success") assert fs.isfile("/remote/output/success") assert fs.cat("/remote/output/success") == b"" # get content as bytestring fs.copy("/remote/output/success", "/remote/output/copy") assert fs.ls("/remote/output", detail=False) == ["/remote/output/success", "/remote/output/copy") fs.rm("/remote/output", recursive=True)
open() method will return a file-like object which can be passed to any other library that expects
to work with python files, or used by your own code as you would a normal python file object.
These will normally be binary-mode only, but may implement internal buffering
in order to limit the number of reads from a remote source. They respect the use of
with contexts. If
pandas installed, for example, you can do the following:
f = fs.open("/remote/path/notes.txt", "rb") lines = f.readline() # read to first b"\n" f.seek(-10, 2) foot = f.read() # read last 10 bytes of file f.close() import pandas as pd with fs.open('/remote/data/myfile.csv') as f: df = pd.read_csv(f, sep='|', header=None)
For many situations, the only function that will be needed is
fsspec.open_files(), which will return
fsspec.core.OpenFile instances created from a single URL and parameters to pass to the backend(s).
This supports text-mode and compression on the fly, and the objects can be serialized for passing between
processes or machines (so long as each has access to the same backend file-system). The protocol (i.e.,
backend) is inferred from the URL passed, and glob characters are expanded in read mode (search for files)
or write mode (create names). Critically, the file on the backend system is not actually opened until the
OpenFile instance is used in a
of = fsspec.open("github://dask:fastparquet@main/test-data/nation.csv", "rt") # of is an OpenFile container object. The "with" context below actually opens it with of as f: # now f is a text-mode file for line in f: # iterate text lines print(line) if "KENYA" in line: break