Add PrefixFileSystem behaviour on open() docstring

fsspec/spec.py

@@ -812,12 +812,12 @@ def put(self, lpath, rpath, recursive=False, callback=_DEFAULT_CALLBACK, **kwarg
             self.put_file(lpath, rpath, **kwargs)
 
     def head(self, path, size=1024):
-        """ Get the first ``size`` bytes from file """
+        """Get the first ``size`` bytes from file"""
         with self.open(path, "rb") as f:
             return f.read(size)
 
     def tail(self, path, size=1024):
-        """ Get the last ``size`` bytes from file """
+        """Get the last ``size`` bytes from file"""
         with self.open(path, "rb") as f:
             f.seek(max(-size, -f.size), 2)
             return f.read()
@@ -879,7 +879,7 @@ def expand_path(self, path, recursive=False, maxdepth=None):
         return list(sorted(out))
 
     def mv(self, path1, path2, recursive=False, maxdepth=None, **kwargs):
-        """ Move file(s) from one location to another """
+        """Move file(s) from one location to another"""
         self.copy(path1, path2, recursive=recursive, maxdepth=maxdepth)
         self.rm(path1, recursive=recursive)
 
@@ -944,6 +944,10 @@ def open(self, path, mode="rb", block_size=None, cache_options=None, **kwargs):
         """
         Return a file-like object from the filesystem
 
+        The file-like object returned ignores an eventual PrefixFileSystem:
+            - the ``.path`` attribute is always an absolute path
+            - the``.fs`` attribute, if present, would be the wrapped file-system
+
         The resultant instance must function correctly in a context ``with``
         block.
 
@@ -1341,14 +1345,14 @@ def discard(self):
         """Throw away temporary file"""
 
     def info(self):
-        """ File information about this path """
+        """File information about this path"""
         if "r" in self.mode:
             return self.details
         else:
             raise ValueError("Info not available while writing")
 
     def tell(self):
-        """ Current file location """
+        """Current file location"""
         return self.loc
 
     def seek(self, loc, whence=0):
@@ -1455,7 +1459,7 @@ def _upload_chunk(self, final=False):
         # may not yet have been initialized, may need to call _initialize_upload
 
     def _initiate_upload(self):
-        """ Create remote file/upload """
+        """Create remote file/upload"""
         pass
 
     def _fetch_range(self, start, end):