From 75f407c0789454e4650ebb11815efba9d2608526 Mon Sep 17 00:00:00 2001
From: Dimitri Papadopoulos
 <3234522+DimitriPapadopoulos@users.noreply.github.com>
Date: Thu, 21 Sep 2023 20:28:46 +0200
Subject: [PATCH] Change legacy string formatting to f-strings

---
 fsspec/archive.py                           |  2 +-
 fsspec/asyn.py                              |  2 +-
 fsspec/caching.py                           | 24 ++++++++++-----------
 fsspec/compression.py                       |  6 ++----
 fsspec/core.py                              |  6 +++---
 fsspec/fuse.py                              |  2 +-
 fsspec/gui.py                               |  7 +++---
 fsspec/implementations/cached.py            | 22 +++++++++----------
 fsspec/implementations/ftp.py               |  8 +++----
 fsspec/implementations/git.py               |  6 +++---
 fsspec/implementations/github.py            | 10 +++------
 fsspec/implementations/http.py              |  8 +++----
 fsspec/implementations/libarchive.py        |  3 +--
 fsspec/implementations/sftp.py              | 18 ++++++++--------
 fsspec/implementations/smb.py               |  4 ++--
 fsspec/implementations/tests/test_cached.py |  4 ++--
 fsspec/implementations/tests/test_ftp.py    |  4 ++--
 fsspec/implementations/tests/test_local.py  |  8 +++----
 fsspec/implementations/tests/test_sftp.py   |  4 ++--
 fsspec/implementations/webhdfs.py           |  4 +---
 fsspec/mapping.py                           |  4 ++--
 fsspec/registry.py                          | 10 ++++-----
 fsspec/spec.py                              | 10 ++++-----
 fsspec/tests/conftest.py                    |  8 +++----
 fsspec/tests/test_spec.py                   |  2 +-
 fsspec/tests/test_utils.py                  |  2 +-
 fsspec/utils.py                             |  4 ++--
 27 files changed, 90 insertions(+), 102 deletions(-)

diff --git a/fsspec/archive.py b/fsspec/archive.py
index dc5c1490b..9bdd8efce 100644
--- a/fsspec/archive.py
+++ b/fsspec/archive.py
@@ -13,7 +13,7 @@ class AbstractArchiveFileSystem(AbstractFileSystem):
     """
 
     def __str__(self):
-        return "<Archive-like object %s at %s>" % (type(self).__name__, id(self))
+        return f"<Archive-like object {type(self).__name__} at {id(self)}>"
 
     __repr__ = __str__
 
diff --git a/fsspec/asyn.py b/fsspec/asyn.py
index 347e262ad..4ac1419f0 100644
--- a/fsspec/asyn.py
+++ b/fsspec/asyn.py
@@ -426,7 +426,7 @@ async def _process_limits(self, url, start, end):
                 end = ""
             if isinstance(end, numbers.Integral):
                 end -= 1  # bytes range is inclusive
-        return "bytes=%s-%s" % (start, end)
+        return f"bytes={start}-{end}"
 
     async def _cat_file(self, path, start=None, end=None, **kwargs):
         raise NotImplementedError
diff --git a/fsspec/caching.py b/fsspec/caching.py
index 41b661ba2..b64240215 100644
--- a/fsspec/caching.py
+++ b/fsspec/caching.py
@@ -222,8 +222,9 @@ def __init__(self, blocksize, fetcher, size, maxblocks=32):
         self._fetch_block_cached = functools.lru_cache(maxblocks)(self._fetch_block)
 
     def __repr__(self):
-        return "<BlockCache blocksize={}, size={}, nblocks={}>".format(
-            self.blocksize, self.size, self.nblocks
+        return (
+            f"<BlockCache blocksize={self.blocksize}, "
+            f"size={self.size}, nblocks={self.nblocks}>"
         )
 
     def cache_info(self):
@@ -277,14 +278,13 @@ def _fetch_block(self, block_number):
         """
         if block_number > self.nblocks:
             raise ValueError(
-                "'block_number={}' is greater than the number of blocks ({})".format(
-                    block_number, self.nblocks
-                )
+                f"'block_number={block_number}' is greater than "
+                f"the number of blocks ({self.nblocks})"
             )
 
         start = block_number * self.blocksize
         end = start + self.blocksize
-        logger.info("BlockCache fetching block %d", block_number)
+        logger.info(f"BlockCache fetching block {block_number}")
         block_contents = super()._fetch(start, end)
         return block_contents
 
@@ -606,8 +606,9 @@ def __init__(self, blocksize, fetcher, size, maxblocks=32):
         self._fetch_future_lock = threading.Lock()
 
     def __repr__(self):
-        return "<BackgroundBlockCache blocksize={}, size={}, nblocks={}>".format(
-            self.blocksize, self.size, self.nblocks
+        return (
+            f"<BackgroundBlockCache blocksize={self.blocksize}, "
+            f"size={self.size}, nblocks={self.nblocks}>"
         )
 
     def cache_info(self):
@@ -719,14 +720,13 @@ def _fetch_block(self, block_number, log_info="sync"):
         """
         if block_number > self.nblocks:
             raise ValueError(
-                "'block_number={}' is greater than the number of blocks ({})".format(
-                    block_number, self.nblocks
-                )
+                f"'block_number={block_number}' is greater than "
+                f"the number of blocks ({self.nblocks})"
             )
 
         start = block_number * self.blocksize
         end = start + self.blocksize
-        logger.info("BlockCache fetching block (%s) %d", log_info, block_number)
+        logger.info(f"BlockCache fetching block ({log_info}) {block_number}")
         block_contents = super()._fetch(start, end)
         return block_contents
 
diff --git a/fsspec/compression.py b/fsspec/compression.py
index 38b1d6dd6..53b7426e2 100644
--- a/fsspec/compression.py
+++ b/fsspec/compression.py
@@ -39,13 +39,11 @@ def register_compression(name, callback, extensions, force=False):
 
     # Validate registration
     if name in compr and not force:
-        raise ValueError("Duplicate compression registration: %s" % name)
+        raise ValueError(f"Duplicate compression registration: {name}")
 
     for ext in extensions:
         if ext in fsspec.utils.compressions and not force:
-            raise ValueError(
-                "Duplicate compression file extension: %s (%s)" % (ext, name)
-            )
+            raise ValueError(f"Duplicate compression file extension: {ext} ({name})")
 
     compr[name] = callback
 
diff --git a/fsspec/core.py b/fsspec/core.py
index 6e5a831ae..23c0db535 100644
--- a/fsspec/core.py
+++ b/fsspec/core.py
@@ -92,7 +92,7 @@ def __reduce__(self):
         )
 
     def __repr__(self):
-        return "<OpenFile '{}'>".format(self.path)
+        return f"<OpenFile '{self.path}'>"
 
     def __enter__(self):
         mode = self.mode.replace("t", "").replace("b", "") + "b"
@@ -195,7 +195,7 @@ def __getitem__(self, item):
         return out
 
     def __repr__(self):
-        return "<List of %s OpenFile instances>" % len(self)
+        return f"<List of {len(self)} OpenFile instances>"
 
 
 def open_files(
@@ -498,7 +498,7 @@ 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)
+        raise ValueError(f"Compression type {compression} not supported")
     return compression
 
 
diff --git a/fsspec/fuse.py b/fsspec/fuse.py
index cdf742a52..8b04626fa 100644
--- a/fsspec/fuse.py
+++ b/fsspec/fuse.py
@@ -275,7 +275,7 @@ def format_help(self):
     for item in args.option or []:
         key, sep, value = item.partition("=")
         if not sep:
-            parser.error(message="Wrong option: {!r}".format(item))
+            parser.error(message=f"Wrong option: {item!r}")
         val = value.lower()
         if val.endswith("[int]"):
             value = int(value[: -len("[int]")])
diff --git a/fsspec/gui.py b/fsspec/gui.py
index 80ccac21f..3c49003e6 100644
--- a/fsspec/gui.py
+++ b/fsspec/gui.py
@@ -70,7 +70,7 @@ class which owns it.
             same name.
         """
         if name not in self.signals:
-            raise ValueError("Attempt to assign an undeclared signal: %s" % name)
+            raise ValueError(f"Attempt to assign an undeclared signal: {name}")
         self._sigs[name] = {
             "widget": widget,
             "callbacks": [],
@@ -141,7 +141,7 @@ def _emit(self, sig, value=None):
 
         Calling of callbacks will halt whenever one returns False.
         """
-        logger.log(self._sigs[sig]["log"], "{}: {}".format(sig, value))
+        logger.log(self._sigs[sig]["log"], f"{sig}: {value}")
         for callback in self._sigs[sig]["callbacks"]:
             if isinstance(callback, str):
                 self._emit(callback)
@@ -153,8 +153,7 @@ def _emit(self, sig, value=None):
                         break
                 except Exception as e:
                     logger.exception(
-                        "Exception (%s) while executing callback for signal: %s"
-                        "" % (e, sig)
+                        f"Exception ({e}) while executing callback for signal: {sig}"
                     )
 
     def show(self, threads=False):
diff --git a/fsspec/implementations/cached.py b/fsspec/implementations/cached.py
index b679cce51..d60f870c5 100644
--- a/fsspec/implementations/cached.py
+++ b/fsspec/implementations/cached.py
@@ -283,10 +283,10 @@ def _open(
             hash, blocks = detail["fn"], detail["blocks"]
             if blocks is True:
                 # stored file is complete
-                logger.debug("Opening local copy of %s" % path)
+                logger.debug(f"Opening local copy of {path}")
                 return open(fn, mode)
             # TODO: action where partial file exists in read-only cache
-            logger.debug("Opening partially cached copy of %s" % path)
+            logger.debug(f"Opening partially cached copy of {path}")
         else:
             hash = self._mapper(path)
             fn = os.path.join(self.storage[-1], hash)
@@ -299,7 +299,7 @@ def _open(
                 "uid": self.fs.ukey(path),
             }
             self._metadata.update_file(path, detail)
-            logger.debug("Creating local sparse file for %s" % path)
+            logger.debug(f"Creating local sparse file for {path}")
 
         # call target filesystems open
         self._mkcache()
@@ -322,9 +322,9 @@ def _open(
         if "blocksize" in detail:
             if detail["blocksize"] != f.blocksize:
                 raise BlocksizeMismatchError(
-                    "Cached file must be reopened with same block"
-                    "size as original (old: %i, new %i)"
-                    "" % (detail["blocksize"], f.blocksize)
+                    f"Cached file must be reopened with same block"
+                    f" size as original (old: {detail['blocksize']},"
+                    f" new {f.blocksize})"
                 )
         else:
             detail["blocksize"] = f.blocksize
@@ -547,7 +547,7 @@ def _make_local_details(self, path):
             "uid": self.fs.ukey(path),
         }
         self._metadata.update_file(path, detail)
-        logger.debug("Copying %s to local cache" % path)
+        logger.debug(f"Copying {path} to local cache")
         return fn
 
     def cat(
@@ -604,7 +604,7 @@ def _open(self, path, mode="rb", **kwargs):
             detail, fn = detail
             _, blocks = detail["fn"], detail["blocks"]
             if blocks is True:
-                logger.debug("Opening local copy of %s" % path)
+                logger.debug(f"Opening local copy of {path}")
 
                 # In order to support downstream filesystems to be able to
                 # infer the compression from the original filename, like
@@ -616,8 +616,8 @@ def _open(self, path, mode="rb", **kwargs):
                 return f
             else:
                 raise ValueError(
-                    "Attempt to open partially cached file %s"
-                    "as a wholly cached file" % path
+                    f"Attempt to open partially cached file {path}"
+                    f" as a wholly cached file"
                 )
         else:
             fn = self._make_local_details(path)
@@ -700,7 +700,7 @@ def _open(self, path, mode="rb", **kwargs):
 
         sha = self._mapper(path)
         fn = os.path.join(self.storage[-1], sha)
-        logger.debug("Copying %s to local cache" % path)
+        logger.debug(f"Copying {path} to local cache")
         kwargs["mode"] = mode
 
         self._mkcache()
diff --git a/fsspec/implementations/ftp.py b/fsspec/implementations/ftp.py
index 7e79877eb..c8e3cf2d2 100644
--- a/fsspec/implementations/ftp.py
+++ b/fsspec/implementations/ftp.py
@@ -156,7 +156,7 @@ def cb(x):
             outfile.write(x)
 
         self.ftp.retrbinary(
-            "RETR %s" % rpath,
+            f"RETR {rpath}",
             blocksize=self.blocksize,
             callback=cb,
         )
@@ -172,7 +172,7 @@ def cb(x):
             out.append(x)
 
         self.ftp.retrbinary(
-            "RETR %s" % path,
+            f"RETR {path}",
             blocksize=self.blocksize,
             rest=start,
             callback=cb,
@@ -321,7 +321,7 @@ def callback(x):
 
         try:
             self.fs.ftp.retrbinary(
-                "RETR %s" % self.path,
+                f"RETR {self.path}",
                 blocksize=self.blocksize,
                 rest=start,
                 callback=callback,
@@ -339,7 +339,7 @@ def callback(x):
     def _upload_chunk(self, final=False):
         self.buffer.seek(0)
         self.fs.ftp.storbinary(
-            "STOR " + self.path, self.buffer, blocksize=self.blocksize, rest=self.offset
+            f"STOR {self.path}", self.buffer, blocksize=self.blocksize, rest=self.offset
         )
         return True
 
diff --git a/fsspec/implementations/git.py b/fsspec/implementations/git.py
index 80c73e066..7c34d93e0 100644
--- a/fsspec/implementations/git.py
+++ b/fsspec/implementations/git.py
@@ -81,7 +81,7 @@ def ls(self, path, detail=True, ref=None, **kwargs):
                             "type": "directory",
                             "name": "/".join([path, obj.name]).lstrip("/"),
                             "hex": obj.hex,
-                            "mode": "%o" % obj.filemode,
+                            "mode": f"{obj.filemode:o}",
                             "size": 0,
                         }
                     )
@@ -91,7 +91,7 @@ def ls(self, path, detail=True, ref=None, **kwargs):
                             "type": "file",
                             "name": "/".join([path, obj.name]).lstrip("/"),
                             "hex": obj.hex,
-                            "mode": "%o" % obj.filemode,
+                            "mode": f"{obj.filemode:o}",
                             "size": obj.size,
                         }
                     )
@@ -102,7 +102,7 @@ def ls(self, path, detail=True, ref=None, **kwargs):
                     "type": "file",
                     "name": obj.name,
                     "hex": obj.hex,
-                    "mode": "%o" % obj.filemode,
+                    "mode": f"{obj.filemode:o}",
                     "size": obj.size,
                 }
             ]
diff --git a/fsspec/implementations/github.py b/fsspec/implementations/github.py
index b148124d7..b5df3f7ab 100644
--- a/fsspec/implementations/github.py
+++ b/fsspec/implementations/github.py
@@ -79,9 +79,7 @@ def repos(cls, org_or_user, is_org=True):
         List of string
         """
         r = requests.get(
-            "https://api.github.com/{part}/{org}/repos".format(
-                part=["users", "orgs"][is_org], org=org_or_user
-            )
+            f"https://api.github.com/{['users', 'orgs'][is_org]}/{org_or_user}/repos"
         )
         r.raise_for_status()
         return [repo["name"] for repo in r.json()]
@@ -90,8 +88,7 @@ def repos(cls, org_or_user, is_org=True):
     def tags(self):
         """Names of tags in the repo"""
         r = requests.get(
-            "https://api.github.com/repos/{org}/{repo}/tags"
-            "".format(org=self.org, repo=self.repo),
+            f"https://api.github.com/repos/{self.org}/{self.repo}/tags",
             **self.kw,
         )
         r.raise_for_status()
@@ -101,8 +98,7 @@ def tags(self):
     def branches(self):
         """Names of branches in the repo"""
         r = requests.get(
-            "https://api.github.com/repos/{org}/{repo}/branches"
-            "".format(org=self.org, repo=self.repo),
+            f"https://api.github.com/repos/{self.org}/{self.repo}/branches",
             **self.kw,
         )
         r.raise_for_status()
diff --git a/fsspec/implementations/http.py b/fsspec/implementations/http.py
index 06551017e..25ecb4450 100644
--- a/fsspec/implementations/http.py
+++ b/fsspec/implementations/http.py
@@ -655,7 +655,7 @@ async def async_fetch_range(self, start, end):
         logger.debug(f"Fetch range for {self}: {start}-{end}")
         kwargs = self.kwargs.copy()
         headers = kwargs.pop("headers", {}).copy()
-        headers["Range"] = "bytes=%i-%i" % (start, end - 1)
+        headers["Range"] = f"bytes={start}-{end - 1}"
         logger.debug(str(self.url) + " : " + headers["Range"])
         r = await self.session.get(
             self.fs.encode_url(self.url), headers=headers, **kwargs
@@ -812,7 +812,7 @@ async def get_range(session, url, start, end, file=None, **kwargs):
     # explicit get a range when we know it must be safe
     kwargs = kwargs.copy()
     headers = kwargs.pop("headers", {}).copy()
-    headers["Range"] = "bytes=%i-%i" % (start, end - 1)
+    headers["Range"] = f"bytes={start}-{end - 1}"
     r = await session.get(url, headers=headers, **kwargs)
     r.raise_for_status()
     async with r:
@@ -831,7 +831,7 @@ async def _file_info(url, session, size_policy="head", **kwargs):
     Default operation is to explicitly allow redirects and use encoding
     'identity' (no compression) to get the true size of the target.
     """
-    logger.debug("Retrieve file size for %s" % url)
+    logger.debug(f"Retrieve file size for {url}")
     kwargs = kwargs.copy()
     ar = kwargs.pop("allow_redirects", True)
     head = kwargs.get("headers", {}).copy()
@@ -844,7 +844,7 @@ async def _file_info(url, session, size_policy="head", **kwargs):
     elif size_policy == "get":
         r = await session.get(url, allow_redirects=ar, **kwargs)
     else:
-        raise TypeError('size_policy must be "head" or "get", got %s' "" % size_policy)
+        raise TypeError(f'size_policy must be "head" or "get", got {size_policy}')
     async with r:
         r.raise_for_status()
 
diff --git a/fsspec/implementations/libarchive.py b/fsspec/implementations/libarchive.py
index 849040423..592e8979d 100644
--- a/fsspec/implementations/libarchive.py
+++ b/fsspec/implementations/libarchive.py
@@ -122,8 +122,7 @@ def __init__(
             files = open_files(fo, protocol=target_protocol, **(target_options or {}))
             if len(files) != 1:
                 raise ValueError(
-                    'Path "{}" did not resolve to exactly'
-                    'one file: "{}"'.format(fo, files)
+                    f'Path "{fo}" did not resolve to exactly one file: "{files}"'
                 )
             fo = files[0]
         self.of = fo
diff --git a/fsspec/implementations/sftp.py b/fsspec/implementations/sftp.py
index 1153e7c6a..aa7ac899a 100644
--- a/fsspec/implementations/sftp.py
+++ b/fsspec/implementations/sftp.py
@@ -48,7 +48,7 @@ def __init__(self, host, **ssh_kwargs):
         self._connect()
 
     def _connect(self):
-        logger.debug("Connecting to SFTP server %s" % self.host)
+        logger.debug(f"Connecting to SFTP server {self.host}")
         self.client = paramiko.SSHClient()
         self.client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
         self.client.connect(self.host, **self.ssh_kwargs)
@@ -66,9 +66,9 @@ def _get_kwargs_from_urls(urlpath):
         return out
 
     def mkdir(self, path, create_parents=False, mode=511):
-        logger.debug("Creating folder %s" % path)
+        logger.debug(f"Creating folder {path}")
         if self.exists(path):
-            raise FileExistsError("File exists: {}".format(path))
+            raise FileExistsError(f"File exists: {path}")
 
         if create_parents:
             self.makedirs(path)
@@ -77,7 +77,7 @@ def mkdir(self, path, create_parents=False, mode=511):
 
     def makedirs(self, path, exist_ok=False, mode=511):
         if self.exists(path) and not exist_ok:
-            raise FileExistsError("File exists: {}".format(path))
+            raise FileExistsError(f"File exists: {path}")
 
         parts = path.split("/")
         path = ""
@@ -88,7 +88,7 @@ def makedirs(self, path, exist_ok=False, mode=511):
                 self.ftp.mkdir(path, mode)
 
     def rmdir(self, path):
-        logger.debug("Removing folder %s" % path)
+        logger.debug(f"Removing folder {path}")
         self.ftp.rmdir(path)
 
     def info(self, path):
@@ -122,7 +122,7 @@ def _decode_stat(stat, parent_path=None):
         return out
 
     def ls(self, path, detail=False):
-        logger.debug("Listing folder %s" % path)
+        logger.debug(f"Listing folder {path}")
         stats = [self._decode_stat(stat, path) for stat in self.ftp.listdir_iter(path)]
         if detail:
             return stats
@@ -131,7 +131,7 @@ def ls(self, path, detail=False):
             return sorted(paths)
 
     def put(self, lpath, rpath, callback=None, **kwargs):
-        logger.debug("Put file %s into %s" % (lpath, rpath))
+        logger.debug(f"Put file {lpath} into {rpath}")
         self.ftp.put(lpath, rpath)
 
     def get_file(self, rpath, lpath, **kwargs):
@@ -146,7 +146,7 @@ def _open(self, path, mode="rb", block_size=None, **kwargs):
             If 0, no buffering, if 1, line buffering, if >1, buffer that many
             bytes, if None use default from paramiko.
         """
-        logger.debug("Opening file %s" % path)
+        logger.debug(f"Opening file {path}")
         if kwargs.get("autocommit", True) is False:
             # writes to temporary file, move on commit
             path2 = "/".join([self.temppath, str(uuid.uuid4())])
@@ -167,7 +167,7 @@ def _rm(self, path):
             self.ftp.remove(path)
 
     def mv(self, old, new):
-        logger.debug("Renaming %s into %s" % (old, new))
+        logger.debug(f"Renaming {old} into {new}")
         self.ftp.posix_rename(old, new)
 
 
diff --git a/fsspec/implementations/smb.py b/fsspec/implementations/smb.py
index a3816773c..5804a6bf5 100644
--- a/fsspec/implementations/smb.py
+++ b/fsspec/implementations/smb.py
@@ -256,13 +256,13 @@ def mv(self, path1, path2, **kwargs):
 
 def _as_unc_path(host, path):
     rpath = path.replace("/", "\\")
-    unc = "\\\\{}{}".format(host, rpath)
+    unc = f"\\\\{host}{rpath}"
     return unc
 
 
 def _as_temp_path(host, path, temppath):
     share = path.split("/")[1]
-    temp_file = "/{}{}/{}".format(share, temppath, uuid.uuid4())
+    temp_file = f"/{share}{temppath}/{uuid.uuid4()}"
     unc = _as_unc_path(host, temp_file)
     return unc
 
diff --git a/fsspec/implementations/tests/test_cached.py b/fsspec/implementations/tests/test_cached.py
index d4e05bdcf..ab92d5cea 100644
--- a/fsspec/implementations/tests/test_cached.py
+++ b/fsspec/implementations/tests/test_cached.py
@@ -926,7 +926,7 @@ def test_with_compression(impl, compression):
     f.close()
 
     with fsspec.open(
-        "%s::%s" % (impl, fn),
+        f"{impl}::{fn}",
         "rb",
         compression=compression,
         **{impl: {"same_names": True, "cache_storage": cachedir}},
@@ -939,7 +939,7 @@ def test_with_compression(impl, compression):
     cachedir = tempfile.mkdtemp()
 
     with fsspec.open(
-        "%s::%s" % (impl, fn),
+        f"{impl}::{fn}",
         "rb",
         **{
             impl: {
diff --git a/fsspec/implementations/tests/test_ftp.py b/fsspec/implementations/tests/test_ftp.py
index af5e6cda1..718b8d2f3 100644
--- a/fsspec/implementations/tests/test_ftp.py
+++ b/fsspec/implementations/tests/test_ftp.py
@@ -77,10 +77,10 @@ def test_write_small(ftp_writable):
 
 def test_with_url(ftp_writable):
     host, port, user, pw = ftp_writable
-    fo = fsspec.open("ftp://{}:{}@{}:{}/out".format(user, pw, host, port), "wb")
+    fo = fsspec.open(f"ftp://{user}:{pw}@{host}:{port}/out", "wb")
     with fo as f:
         f.write(b"hello")
-    fo = fsspec.open("ftp://{}:{}@{}:{}/out".format(user, pw, host, port), "rb")
+    fo = fsspec.open(f"ftp://{user}:{pw}@{host}:{port}/out", "rb")
     with fo as f:
         assert f.read() == b"hello"
 
diff --git a/fsspec/implementations/tests/test_local.py b/fsspec/implementations/tests/test_local.py
index 961537520..268cab422 100644
--- a/fsspec/implementations/tests/test_local.py
+++ b/fsspec/implementations/tests/test_local.py
@@ -79,7 +79,7 @@ def filetexts(d, open=open, mode="t"):
 
 def test_urlpath_inference_strips_protocol(tmpdir):
     tmpdir = make_path_posix(str(tmpdir))
-    paths = ["/".join([tmpdir, "test.%02d.csv" % i]) for i in range(20)]
+    paths = ["/".join([tmpdir, f"test.{i:02d}.csv"]) for i in range(20)]
 
     for path in paths:
         with open(path, "wb") as f:
@@ -425,11 +425,11 @@ def test_recursive_get_put(tmpdir):
     fs.touch(tmpdir + "/a1/a2/a3/afile")
     fs.touch(tmpdir + "/a1/afile")
 
-    fs.get("file://{0}/a1".format(tmpdir), tmpdir + "/b1", recursive=True)
+    fs.get(f"file://{tmpdir}/a1", tmpdir + "/b1", recursive=True)
     assert fs.isfile(tmpdir + "/b1/afile")
     assert fs.isfile(tmpdir + "/b1/a2/a3/afile")
 
-    fs.put(tmpdir + "/b1", "file://{0}/c1".format(tmpdir), recursive=True)
+    fs.put(tmpdir + "/b1", f"file://{tmpdir}/c1", recursive=True)
     assert fs.isfile(tmpdir + "/c1/afile")
     assert fs.isfile(tmpdir + "/c1/a2/a3/afile")
 
@@ -652,7 +652,7 @@ def test_iterable(tmpdir):
     fn = os.path.join(tmpdir, "test")
     with open(fn, "wb") as f:
         f.write(data)
-    of = fsspec.open("file://%s" % fn, "rb")
+    of = fsspec.open(f"file://{fn}", "rb")
     with of as f:
         out = list(f)
     assert b"".join(out) == data
diff --git a/fsspec/implementations/tests/test_sftp.py b/fsspec/implementations/tests/test_sftp.py
index 6fe1ea88a..3ddc524bd 100644
--- a/fsspec/implementations/tests/test_sftp.py
+++ b/fsspec/implementations/tests/test_sftp.py
@@ -12,7 +12,7 @@
 
 
 def stop_docker(name):
-    cmd = shlex.split('docker ps -a -q --filter "name=%s"' % name)
+    cmd = shlex.split(f'docker ps -a -q --filter "name={name}"')
     cid = subprocess.check_output(cmd).strip().decode()
     if cid:
         subprocess.call(["docker", "rm", "-f", cid])
@@ -45,7 +45,7 @@ def ssh():
     ]
     name = "fsspec_sftp"
     stop_docker(name)
-    cmd = "docker run -d -p 9200:22 --name {} ubuntu:16.04 sleep 9000".format(name)
+    cmd = f"docker run -d -p 9200:22 --name {name} ubuntu:16.04 sleep 9000"
     cid = subprocess.check_output(shlex.split(cmd)).strip().decode()
     for cmd in cmds:
         subprocess.call(["docker", "exec", cid] + shlex.split(cmd))
diff --git a/fsspec/implementations/webhdfs.py b/fsspec/implementations/webhdfs.py
index cc595934f..fd3b075c7 100644
--- a/fsspec/implementations/webhdfs.py
+++ b/fsspec/implementations/webhdfs.py
@@ -89,9 +89,7 @@ def __init__(
         if self._cached:
             return
         super().__init__(**kwargs)
-        self.url = "{protocol}://{host}:{port}/webhdfs/v1".format(
-            protocol="https" if use_https else "http", host=host, port=port
-        )
+        self.url = f"{'https' if use_https else 'http'}://{host}:{port}/webhdfs/v1"
         self.kerb = kerberos
         self.kerb_kwargs = kerb_kwargs or {}
         self.pars = {}
diff --git a/fsspec/mapping.py b/fsspec/mapping.py
index 2b75c2e41..b9822ae17 100644
--- a/fsspec/mapping.py
+++ b/fsspec/mapping.py
@@ -54,8 +54,8 @@ def __init__(self, root, fs, check=False, create=False, missing_exceptions=None)
         if check:
             if not self.fs.exists(root):
                 raise ValueError(
-                    "Path %s does not exist. Create "
-                    " with the ``create=True`` keyword" % root
+                    f"Path {root} does not exist. Create "
+                    f" with the ``create=True`` keyword"
                 )
             self.fs.touch(root + "/a")
             self.fs.rm(root + "/a")
diff --git a/fsspec/registry.py b/fsspec/registry.py
index 851bc65bc..126d9a522 100644
--- a/fsspec/registry.py
+++ b/fsspec/registry.py
@@ -38,20 +38,20 @@ def register_implementation(name, cls, clobber=False, errtxt=None):
         if name in known_implementations and clobber is False:
             if cls != known_implementations[name]["class"]:
                 raise ValueError(
-                    "Name (%s) already in the known_implementations and clobber "
-                    "is False" % name
+                    f"Name ({name}) already in the known_implementations and clobber "
+                    f"is False"
                 )
         else:
             known_implementations[name] = {
                 "class": cls,
-                "err": errtxt or "%s import failed for protocol %s" % (cls, name),
+                "err": errtxt or f"{cls} import failed for protocol {name}",
             }
 
     else:
         if name in registry and clobber is False:
             if _registry[name] is not cls:
                 raise ValueError(
-                    "Name (%s) already in the registry and clobber is False" % name
+                    f"Name ({name}) already in the registry and clobber is False"
                 )
         else:
             _registry[name] = cls
@@ -228,7 +228,7 @@ def get_filesystem_class(protocol):
 
     if protocol not in registry:
         if protocol not in known_implementations:
-            raise ValueError("Protocol not known: %s" % protocol)
+            raise ValueError(f"Protocol not known: {protocol}")
         bit = known_implementations[protocol]
         try:
             register_implementation(protocol, _import_class(bit["class"]))
diff --git a/fsspec/spec.py b/fsspec/spec.py
index a205cb2b6..f491098a8 100644
--- a/fsspec/spec.py
+++ b/fsspec/spec.py
@@ -1187,9 +1187,7 @@ def expand_path(self, path, recursive=False, maxdepth=None, **kwargs):
     def mv(self, path1, path2, recursive=False, maxdepth=None, **kwargs):
         """Move file(s) from one location to another"""
         if path1 == path2:
-            logger.debug(
-                "%s mv: The paths are the same, so no files were moved." % (self)
-            )
+            logger.debug(f"{self} mv: The paths are the same, so no files were moved.")
         else:
             self.copy(path1, path2, recursive=recursive, maxdepth=maxdepth)
             self.rm(path1, recursive=recursive)
@@ -1744,7 +1742,7 @@ def seek(self, loc, whence=0):
         elif whence == 2:
             nloc = self.size + loc
         else:
-            raise ValueError("invalid whence (%s, should be 0, 1 or 2)" % whence)
+            raise ValueError(f"invalid whence ({whence}, should be 0, 1 or 2)")
         if nloc < 0:
             raise ValueError("Seek before start of file")
         self.loc = nloc
@@ -1851,7 +1849,7 @@ def read(self, length=-1):
             length = self.size - self.loc
         if self.closed:
             raise ValueError("I/O operation on closed file.")
-        logger.debug("%s read: %i - %i" % (self, self.loc, self.loc + length))
+        logger.debug(f"{self} read: {self.loc} - {self.loc + length}")
         if length == 0:
             # don't even bother calling fetch
             return b""
@@ -1966,7 +1964,7 @@ def __del__(self):
             self.close()
 
     def __str__(self):
-        return "<File-like object %s, %s>" % (type(self.fs).__name__, self.path)
+        return f"<File-like object {type(self.fs).__name__}, {self.path}>"
 
     __repr__ = __str__
 
diff --git a/fsspec/tests/conftest.py b/fsspec/tests/conftest.py
index 2c7a1742b..f5056335e 100644
--- a/fsspec/tests/conftest.py
+++ b/fsspec/tests/conftest.py
@@ -11,7 +11,7 @@
 requests = pytest.importorskip("requests")
 port = 9898
 data = b"\n".join([b"some test data"] * 1000)
-realfile = "http://127.0.0.1:%i/index/realfile" % port
+realfile = f"http://127.0.0.1:{port}/index/realfile"
 index = b'<a href="%s">Link</a>' % realfile.encode()
 listing = open(
     os.path.join(os.path.dirname(__file__), "data", "listing.html"), "rb"
@@ -61,7 +61,7 @@ def do_GET(self):
             return self._respond(404)
 
         status = 200
-        content_range = "bytes 0-%i/%i" % (len(file_data) - 1, len(file_data))
+        content_range = f"bytes 0-{len(file_data) - 1}/{len(file_data)}"
         if ("Range" in self.headers) and ("ignore_range" not in self.headers):
             ran = self.headers["Range"]
             b, ran = ran.split("=")
@@ -139,7 +139,7 @@ def do_HEAD(self):
             self._respond(200, response_headers)
         elif "give_range" in self.headers:
             self._respond(
-                200, {"Content-Range": "0-%i/%i" % (len(file_data) - 1, len(file_data))}
+                200, {f"Content-Range": "0-{len(file_data) - 1}/{len(file_data)}"}
             )
         elif "give_etag" in self.headers:
             self._respond(200, {"ETag": "xxx"})
@@ -155,7 +155,7 @@ def serve():
     th.daemon = True
     th.start()
     try:
-        yield "http://127.0.0.1:%i" % port
+        yield f"http://127.0.0.1:{port}"
     finally:
         httpd.socket.close()
         httpd.shutdown()
diff --git a/fsspec/tests/test_spec.py b/fsspec/tests/test_spec.py
index 38e6dabb1..f76bbef76 100644
--- a/fsspec/tests/test_spec.py
+++ b/fsspec/tests/test_spec.py
@@ -420,7 +420,7 @@ def __getitem__(self, name):
         for item in self._fs_contents:
             if item["name"] == name:
                 return item
-        raise IndexError("{name} not found!".format(name=name))
+        raise IndexError(f"{name} not found!")
 
     def ls(self, path, detail=True, refresh=True, **kwargs):
         if kwargs.pop("strip_proto", True):
diff --git a/fsspec/tests/test_utils.py b/fsspec/tests/test_utils.py
index c83eeea0c..b5732e9f1 100644
--- a/fsspec/tests/test_utils.py
+++ b/fsspec/tests/test_utils.py
@@ -206,7 +206,7 @@ def test_infer_options():
     # - Parsing doesn't lowercase the bucket
     # - The bucket is included in path
     for protocol in ["s3", "s3a", "gcs", "gs"]:
-        options = infer_storage_options("%s://Bucket-name.com/test.csv" % protocol)
+        options = infer_storage_options(f"{protocol}://Bucket-name.com/test.csv")
         assert options["path"] == "Bucket-name.com/test.csv"
 
     with pytest.raises(KeyError):
diff --git a/fsspec/utils.py b/fsspec/utils.py
index 593a40d2a..9e52ffe51 100644
--- a/fsspec/utils.py
+++ b/fsspec/utils.py
@@ -106,8 +106,8 @@ def update_storage_options(options, inherited=None):
         for collision in collisions:
             if options.get(collision) != inherited.get(collision):
                 raise KeyError(
-                    "Collision between inferred and specified storage "
-                    "option:\n%s" % collision
+                    f"Collision between inferred and specified storage "
+                    f"option:\n{collision}"
                 )
     options.update(inherited)