Example of refactoring using rope library.

tools/telemetry/third_party/rope/rope/base/resources.py

+"""Files and folders in a project are represented as resource objects.
+
+Files and folders are access through `Resource` objects. `Resource` has
+two subclasses: `File` and `Folder`. What we care about is that
+refactorings and `rope.base.change.Change`s use resources.
+
+There are two options to create a `Resource` for a path in a project.
+Note that in these examples `path` is the path to a file or folder
+relative to the project's root. A project's root folder is represented
+by an empty string.
+
+  1) Use the `rope.base.Project.get_resource()` method. E.g.:
+
+       myresource = myproject.get_resource(path)
+
+
+  2) Use the `rope.base.libutils` module. `libutils` has a function
+     named `path_to_resource()`. It takes a project and a path:
+
+       from rope.base import libutils
+
+       myresource = libutils.path_to_resource(myproject, path)
+
+Once we have a `Resource`, we can retrieve information from it, like
+getting the path relative to the project's root (via `path`), reading
+from and writing to the resource, moving the resource, etc.
+"""
+
+import os
+import re
+
+from rope.base import change
+from rope.base import exceptions
+from rope.base import fscommands
+
+
+class Resource(object):
+    """Represents files and folders in a project"""
+
+    def __init__(self, project, path):
+        self.project = project
+        self._path = path
+
+    def move(self, new_location):
+        """Move resource to `new_location`"""
+        self._perform_change(change.MoveResource(self, new_location),
+                             'Moving <%s> to <%s>' % (self.path, new_location))
+
+    def remove(self):
+        """Remove resource from the project"""
+        self._perform_change(change.RemoveResource(self),
+                             'Removing <%s>' % self.path)
+
+    def is_folder(self):
+        """Return true if the resource is a folder"""
+
+    def create(self):
+        """Create this resource"""
+
+    def exists(self):
+        return os.path.exists(self.real_path)
+
+    @property
+    def parent(self):
+        parent = '/'.join(self.path.split('/')[0:-1])
+        return self.project.get_folder(parent)
+
+    @property
+    def path(self):
+        """Return the path of this resource relative to the project root
+
+        The path is the list of parent directories separated by '/' followed
+        by the resource name.
+        """
+        return self._path
+
+    @property
+    def name(self):
+        """Return the name of this resource"""
+        return self.path.split('/')[-1]
+
+    @property
+    def real_path(self):
+        """Return the file system path of this resource"""
+        return self.project._get_resource_path(self.path)
+
+    def __eq__(self, obj):
+        return self.__class__ == obj.__class__ and self.path == obj.path
+
+    def __ne__(self, obj):
+        return not self.__eq__(obj)
+
+    def __hash__(self):
+        return hash(self.path)
+
+    def _perform_change(self, change_, description):
+        changes = change.ChangeSet(description)
+        changes.add_change(change_)
+        self.project.do(changes)
+
+
+class File(Resource):
+    """Represents a file"""
+
+    def __init__(self, project, name):
+        super(File, self).__init__(project, name)
+
+    def read(self):
+        data = self.read_bytes()
+        try:
+            return fscommands.file_data_to_unicode(data)
+        except UnicodeDecodeError as e:
+            raise exceptions.ModuleDecodeError(self.path, e.reason)
+
+    def read_bytes(self):
+        return open(self.real_path, 'rb').read()
+
+    def write(self, contents):
+        try:
+            if contents == self.read():
+                return
+        except IOError:
+            pass
+        self._perform_change(change.ChangeContents(self, contents),
+                             'Writing file <%s>' % self.path)
+
+    def is_folder(self):
+        return False
+
+    def create(self):
+        self.parent.create_file(self.name)
+
+
+class Folder(Resource):
+    """Represents a folder"""
+
+    def __init__(self, project, name):
+        super(Folder, self).__init__(project, name)
+
+    def is_folder(self):
+        return True
+
+    def get_children(self):
+        """Return the children of this folder"""
+        try:
+            children = os.listdir(self.real_path)
+        except OSError:
+            return []
+        result = []
+        for name in children:
+            try:
+                child = self.get_child(name)
+            except exceptions.ResourceNotFoundError:
+                continue
+            if not self.project.is_ignored(child):
+                result.append(self.get_child(name))
+        return result
+
+    def create_file(self, file_name):
+        self._perform_change(
+            change.CreateFile(self, file_name),
+            'Creating file <%s>' % self._get_child_path(file_name))
+        return self.get_child(file_name)
+
+    def create_folder(self, folder_name):
+        self._perform_change(
+            change.CreateFolder(self, folder_name),
+            'Creating folder <%s>' % self._get_child_path(folder_name))
+        return self.get_child(folder_name)
+
+    def _get_child_path(self, name):
+        if self.path:
+            return self.path + '/' + name
+        else:
+            return name
+
+    def get_child(self, name):
+        return self.project.get_resource(self._get_child_path(name))
+
+    def has_child(self, name):
+        try:
+            self.get_child(name)
+            return True
+        except exceptions.ResourceNotFoundError:
+            return False
+
+    def get_files(self):
+        return [resource for resource in self.get_children()
+                if not resource.is_folder()]
+
+    def get_folders(self):
+        return [resource for resource in self.get_children()
+                if resource.is_folder()]
+
+    def contains(self, resource):
+        if self == resource:
+            return False
+        return self.path == '' or resource.path.startswith(self.path + '/')
+
+    def create(self):
+        self.parent.create_folder(self.name)
+
+
+class _ResourceMatcher(object):
+
+    def __init__(self):
+        self.patterns = []
+        self._compiled_patterns = []
+
+    def set_patterns(self, patterns):
+        """Specify which resources to match
+
+        `patterns` is a `list` of `str`\s that can contain ``*`` and
+        ``?`` signs for matching resource names.
+
+        """
+        self._compiled_patterns = None
+        self.patterns = patterns
+
+    def _add_pattern(self, pattern):
+        re_pattern = pattern.replace('.', '\\.').\
+            replace('*', '[^/]*').replace('?', '[^/]').\
+            replace('//', '/(.*/)?')
+        re_pattern = '^(.*/)?' + re_pattern + '(/.*)?$'
+        self.compiled_patterns.append(re.compile(re_pattern))
+
+    def does_match(self, resource):
+        for pattern in self.compiled_patterns:
+            if pattern.match(resource.path):
+                return True
+        path = os.path.join(resource.project.address,
+                            *resource.path.split('/'))
+        if os.path.islink(path):
+            return True
+        return False
+
+    @property
+    def compiled_patterns(self):
+        if self._compiled_patterns is None:
+            self._compiled_patterns = []
+            for pattern in self.patterns:
+                self._add_pattern(pattern)
+        return self._compiled_patterns