Merge pull request #2128 from pared/2119

pathinfo: extract relative path method to standalone method

dvc/command/pipeline.py

@@ -1,9 +1,9 @@
 from __future__ import unicode_literals
 
+from dvc.utils import relpath
 from dvc.utils.compat import str
 
 import argparse
-import os
 import logging
 
 from dvc.exceptions import DvcException
@@ -21,7 +21,7 @@ class CmdPipelineShow(CmdBase):
         stage = Stage.load(self.repo, target)
         G = self.repo.graph()[0]
         stages = networkx.get_node_attributes(G, "stage")
-        node = os.path.relpath(stage.path, self.repo.root_dir)
+        node = relpath(stage.path, self.repo.root_dir)
         nodes = networkx.dfs_postorder_nodes(G, node)
 
         if locked:
@@ -41,7 +41,7 @@ class CmdPipelineShow(CmdBase):
         from dvc.stage import Stage
 
         stage = Stage.load(self.repo, target)
-        node = os.path.relpath(stage.path, self.repo.root_dir)
+        node = relpath(stage.path, self.repo.root_dir)
 
         pipelines = list(
             filter(lambda g: node in g.nodes(), self.repo.pipelines())

dvc/command/root.py

@@ -1,19 +1,18 @@
 from __future__ import unicode_literals
 
 import argparse
-import os
 import logging
 
 from dvc.repo import Repo
 from dvc.command.base import CmdBaseNoRepo, append_doc_link
-
+from dvc.utils import relpath
 
 logger = logging.getLogger(__name__)
 
 
 class CmdRoot(CmdBaseNoRepo):
     def run(self):
-        logger.info(os.path.relpath(Repo.find_root()))
+        logger.info(relpath(Repo.find_root()))
         return 0
 
 

dvc/exceptions.py

@@ -4,9 +4,10 @@ from __future__ import unicode_literals
 
 from dvc.utils.compat import str, builtin_str
 
-import os
 import traceback
 
+from dvc.utils import relpath
+
 
 class DvcException(Exception):
     """Base class for all dvc exceptions.
@@ -62,7 +63,7 @@ class OutputNotFoundError(DvcException):
     def __init__(self, output):
         super(OutputNotFoundError, self).__init__(
             "unable to find stage file with output '{path}'".format(
-                path=os.path.relpath(output)
+                path=relpath(output)
             )
         )
 
@@ -198,7 +199,7 @@ class BadMetricError(DvcException):
     def __init__(self, path):
         super(BadMetricError, self).__init__(
             "'{}' does not exist, not a metric or is malformed".format(
-                os.path.relpath(path)
+                relpath(path)
             )
         )
 
@@ -213,7 +214,7 @@ class NoMetricsError(DvcException):
 
 class StageFileCorruptedError(DvcException):
     def __init__(self, path, cause=None):
-        path = os.path.relpath(path)
+        path = relpath(path)
         super(StageFileCorruptedError, self).__init__(
             "unable to read stage file: {} "
             "YAML file structure is corrupted".format(path),

dvc/ignore.py

@@ -3,6 +3,7 @@ from __future__ import unicode_literals
 import os
 
 from dulwich.ignore import match_pattern, read_ignore_patterns
+from dvc.utils import relpath
 from dvc.utils.compat import cast_bytes
 from dvc.utils.fs import get_parent_dirs_up_to
 
@@ -55,15 +56,15 @@ class DvcIgnoreFromFile(DvcIgnore):
         return dirs, files
 
     def get_match(self, abs_path):
-        rel_path = os.path.relpath(abs_path, self.dirname)
+        relative_path = relpath(abs_path, self.dirname)
         if os.name == "nt":
-            rel_path = rel_path.replace("\\", "/")
-        rel_path = cast_bytes(rel_path, "utf-8")
+            relative_path = relative_path.replace("\\", "/")
+        relative_path = cast_bytes(relative_path, "utf-8")
 
         for pattern in self.patterns:
             if match_pattern(
-                rel_path, pattern
-            ) and self._no_negate_pattern_matches(rel_path):
+                relative_path, pattern
+            ) and self._no_negate_pattern_matches(relative_path):
                 return (abs_path, pattern, self.ignore_file_path)
         return None
 

dvc/path_info.py

@@ -6,12 +6,14 @@ import posixpath
 from funcy import cached_property
 
 from dvc.utils.compat import str, builtin_str, basestring, is_py2
-from dvc.utils.compat import pathlib, fspath_py35, urlparse
+from dvc.utils.compat import pathlib, urlparse
 
 
 # On Python 2.7/Windows sys.getfilesystemencoding() is set to mbcs,
 # which is lossy, thus we can't use that,
 # see https://github.com/mcmtroffaes/pathlib2/issues/56.
+from dvc.utils import relpath
+
 if is_py2:
     fs_encoding = "utf-8"
 
@@ -31,10 +33,7 @@ class PathInfo(pathlib.PurePath):
 
     def __str__(self):
         path = self.__fspath__()
-        # Windows path on different drive than curdir doesn't have relpath
-        if os.name == "nt" and not os.path.commonprefix([os.getcwd(), path]):
-            return path
-        return os.path.relpath(path)
+        return relpath(path)
 
     def __repr__(self):
         return builtin_str("{}: '{}'").format(type(self).__name__, self)
@@ -51,9 +50,7 @@ class PathInfo(pathlib.PurePath):
     url = fspath
 
     def relpath(self, other):
-        return self.__class__(
-            os.path.relpath(fspath_py35(self), fspath_py35(other))
-        )
+        return self.__class__(relpath(self, other))
 
     def isin(self, other):
         if isinstance(other, basestring):

dvc/remote/base.py

@@ -16,7 +16,7 @@ import dvc.prompt as prompt
 from dvc.config import Config
 from dvc.exceptions import DvcException, ConfirmRemoveError
 from dvc.progress import progress, ProgressCallback
-from dvc.utils import LARGE_DIR_SIZE, tmp_fname, to_chunks, move
+from dvc.utils import LARGE_DIR_SIZE, tmp_fname, to_chunks, move, relpath
 from dvc.state import StateBase
 from dvc.path_info import PathInfo, URLInfo
 
@@ -148,7 +148,7 @@ class RemoteBASE(object):
 
             for fname in files:
                 file_info = self.path_cls(root) / fname
-                relpath = file_info.relative_to(path_info)
+                relative_path = file_info.relative_to(path_info)
                 dir_info.append(
                     {
                         # NOTE: this is lossy transformation:
@@ -159,7 +159,7 @@ class RemoteBASE(object):
                         #
                         # Yes, this is a BUG, as long as we permit "/" in
                         # filenames on Windows and "\" on Unix
-                        self.PARAM_RELPATH: relpath.as_posix(),
+                        self.PARAM_RELPATH: relative_path.as_posix(),
                         self.PARAM_CHECKSUM: self.get_file_checksum(file_info),
                     }
                 )
@@ -221,13 +221,13 @@ class RemoteBASE(object):
 
         if not isinstance(d, list):
             msg = "dir cache file format error '{}' [skipping the file]"
-            logger.error(msg.format(os.path.relpath(path)))
+            logger.error(msg.format(relpath(path)))
             return []
 
         for info in d:
             # NOTE: here is a BUG, see comment to .as_posix() below
-            relpath = self.path_cls.from_posix(info[self.PARAM_RELPATH])
-            info[self.PARAM_RELPATH] = relpath.fspath
+            relative_path = self.path_cls.from_posix(info[self.PARAM_RELPATH])
+            info[self.PARAM_RELPATH] = relative_path.fspath
 
         return d
 
@@ -699,10 +699,10 @@ class RemoteBASE(object):
         logger.debug("Linking directory '{}'.".format(path_info))
 
         for entry in dir_info:
-            relpath = entry[self.PARAM_RELPATH]
+            relative_path = entry[self.PARAM_RELPATH]
             entry_checksum = entry[self.PARAM_CHECKSUM]
             entry_cache_info = self.checksum_to_path_info(entry_checksum)
-            entry_info = path_info / relpath
+            entry_info = path_info / relative_path
 
             entry_checksum_info = {self.PARAM_CHECKSUM: entry_checksum}
             if self.changed(entry_info, entry_checksum_info):

dvc/remote/config.py

@@ -2,6 +2,7 @@ import os
 import logging
 import posixpath
 
+from dvc.utils import relpath
 from dvc.utils.compat import urlparse
 from dvc.config import Config, ConfigError
 
@@ -85,7 +86,7 @@ class RemoteConfig(object):
         """
         if os.path.isabs(path):
             return path
-        return os.path.relpath(path, os.path.dirname(config_file))
+        return relpath(path, os.path.dirname(config_file))
 
     def add(self, name, url, default=False, force=False, level=None):
         from dvc.remote import _get, RemoteLOCAL

dvc/remote/local/__init__.py

@@ -28,6 +28,7 @@ from dvc.utils import (
     tmp_fname,
     file_md5,
     walk_files,
+    relpath,
 )
 from dvc.config import Config
 from dvc.exceptions import DvcException
@@ -464,11 +465,7 @@ class RemoteLOCAL(RemoteBASE):
             # would get only the part of file. So, at first, the file should be
             # copied with the temporary name, and then original file should be
             # replaced by new.
-            copyfile(
-                path,
-                tmp,
-                name="Unprotecting '{}'".format(os.path.relpath(path)),
-            )
+            copyfile(path, tmp, name="Unprotecting '{}'".format(relpath(path)))
             remove(path)
             os.rename(tmp, path)
 
@@ -536,9 +533,9 @@ class RemoteLOCAL(RemoteBASE):
             entry_cache_info = self.checksum_to_path_info(
                 entry[self.PARAM_CHECKSUM]
             )
-            relpath = entry[self.PARAM_RELPATH]
+            relative_path = entry[self.PARAM_RELPATH]
             self.link(
-                entry_cache_info, unpacked_dir_info / relpath, "hardlink"
+                entry_cache_info, unpacked_dir_info / relative_path, "hardlink"
             )
 
         self.state.save(unpacked_dir_info, checksum)

dvc/repo/__init__.py

@@ -12,6 +12,7 @@ from dvc.exceptions import (
 from dvc.ignore import DvcIgnoreFileHandler
 from dvc.path_info import PathInfo
 from dvc.utils.compat import open as _open
+from dvc.utils import relpath
 
 logger = logging.getLogger(__name__)
 
@@ -167,7 +168,7 @@ class Repo(object):
         if not with_deps:
             return [stage]
 
-        node = os.path.relpath(stage.path, self.root_dir)
+        node = relpath(stage.path, self.root_dir)
         G = self._get_pipeline(node)
 
         ret = []
@@ -324,7 +325,7 @@ class Repo(object):
                     raise StagePathAsOutputError(stage.wdir, stage.relpath)
 
         for stage in stages:
-            node = os.path.relpath(stage.path, self.root_dir)
+            node = relpath(stage.path, self.root_dir)
 
             G.add_node(node, stage=stage)
             G_active.add_node(node, stage=stage)
@@ -339,7 +340,7 @@ class Repo(object):
                         continue
 
                     dep_stage = out.stage
-                    dep_node = os.path.relpath(dep_stage.path, self.root_dir)
+                    dep_node = relpath(dep_stage.path, self.root_dir)
                     G.add_node(dep_node, stage=dep_stage)
                     G.add_edge(node, dep_node)
                     if not stage.locked:

dvc/repo/init.py

@@ -8,7 +8,7 @@ from dvc.scm import SCM, NoSCM
 from dvc.config import Config
 from dvc.exceptions import InitError
 from dvc.utils import boxify
-
+from dvc.utils import relpath
 
 logger = logging.getLogger(__name__)
 
@@ -74,7 +74,7 @@ def init(root_dir=os.curdir, no_scm=False, force=False):
         if not force:
             raise InitError(
                 "'{repo}' exists. Use '-f' to force.".format(
-                    repo=os.path.relpath(dvc_dir)
+                    repo=relpath(dvc_dir)
                 )
             )
 

dvc/repo/reproduce.py

@@ -5,7 +5,7 @@ import logging
 
 from dvc.exceptions import ReproductionError
 from dvc.repo.scm_context import scm_context
-
+from dvc.utils import relpath
 
 logger = logging.getLogger(__name__)
 
@@ -67,7 +67,7 @@ def reproduce(
     elif pipeline or all_pipelines:
         if pipeline:
             stage = Stage.load(self, target)
-            node = os.path.relpath(stage.path, self.root_dir)
+            node = relpath(stage.path, self.root_dir)
             pipelines = [self._get_pipeline(node)]
         else:
             pipelines = self.pipelines()
@@ -115,7 +115,7 @@ def _reproduce(
     stage = Stage.load(self, target)
     G = self.graph()[1]
     stages = nx.get_node_attributes(G, "stage")
-    node = os.path.relpath(stage.path, self.root_dir)
+    node = relpath(stage.path, self.root_dir)
 
     if single_item:
         ret = _reproduce_stage(

dvc/scm/git/__init__.py

@@ -6,7 +6,7 @@ import os
 import logging
 
 from dvc.utils.compat import str, open
-from dvc.utils import fix_env
+from dvc.utils import fix_env, relpath
 from dvc.scm.base import (
     Base,
     SCMError,
@@ -92,7 +92,7 @@ class Git(Base):
                 msg.format(self.GITIGNORE, path, ignore_file_dir)
             )
 
-        entry = os.path.relpath(path, ignore_file_dir).replace(os.sep, "/")
+        entry = relpath(path, ignore_file_dir).replace(os.sep, "/")
         # NOTE: using '/' prefix to make path unambiguous
         if len(entry) > 0 and entry[0] != "/":
             entry = "/" + entry
@@ -125,14 +125,12 @@ class Git(Base):
         if self._ignored(entry, gitignore):
             return
 
-        msg = "Adding '{}' to '{}'.".format(
-            os.path.relpath(path), os.path.relpath(gitignore)
-        )
+        msg = "Adding '{}' to '{}'.".format(relpath(path), relpath(gitignore))
         logger.info(msg)
 
         self._add_entry_to_gitignore(entry, gitignore)
 
-        self.track_file(os.path.relpath(gitignore))
+        self.track_file(relpath(gitignore))
 
         self.ignored_paths.append(path)
 
@@ -163,7 +161,7 @@ class Git(Base):
         with open(gitignore, "w") as fobj:
             fobj.writelines(filtered)
 
-        self.track_file(os.path.relpath(gitignore))
+        self.track_file(relpath(gitignore))
 
     def add(self, paths):
         # NOTE: GitPython is not currently able to handle index version >= 3.
@@ -202,7 +200,7 @@ class Git(Base):
     def is_tracked(self, path):
         # it is equivalent to `bool(self.git.git.ls_files(path))` by
         # functionality, but ls_files fails on unicode filenames
-        path = os.path.relpath(path, self.root_dir)
+        path = relpath(path, self.root_dir)
         return path in [i[0] for i in self.git.index.entries]
 
     def is_dirty(self):

dvc/scm/git/tree.py

@@ -2,6 +2,7 @@ import errno
 import os
 
 from dvc.ignore import DvcIgnoreFilter
+from dvc.utils import relpath
 from dvc.utils.compat import StringIO, BytesIO
 from dvc.exceptions import DvcException
 
@@ -32,14 +33,14 @@ class GitTree(BaseTree):
 
     def open(self, path, binary=False):
 
-        relpath = os.path.relpath(path, self.git.working_dir)
+        relative_path = relpath(path, self.git.working_dir)
 
         obj = self.git_object_by_path(path)
         if obj is None:
             msg = "No such file in branch '{}'".format(self.rev)
-            raise IOError(errno.ENOENT, msg, relpath)
+            raise IOError(errno.ENOENT, msg, relative_path)
         if obj.mode == GIT_MODE_DIR:
-            raise IOError(errno.EISDIR, "Is a directory", relpath)
+            raise IOError(errno.EISDIR, "Is a directory", relative_path)
 
         # GitPython's obj.data_stream is a fragile thing, it is better to
         # read it immediately, also it needs to be to decoded if we follow
@@ -98,7 +99,7 @@ class GitTree(BaseTree):
     def git_object_by_path(self, path):
         import git
 
-        path = os.path.relpath(os.path.realpath(path), self.git.working_dir)
+        path = relpath(os.path.realpath(path), self.git.working_dir)
         assert path.split(os.sep, 1)[0] != ".."
 
         self._try_fetch_from_remote()

dvc/stage.py

@@ -8,6 +8,7 @@ import os
 import subprocess
 import logging
 
+from dvc.utils import relpath
 from dvc.utils.compat import pathlib
 from dvc.utils.fs import contains_symlink_up_to
 from schema import Schema, SchemaError, Optional, Or, And
@@ -176,7 +177,7 @@ class Stage(object):
 
     @property
     def relpath(self):
-        return os.path.relpath(self.path)
+        return relpath(self.path)
 
     @property
     def is_data_source(self):
@@ -553,7 +554,7 @@ class Stage(object):
             raise StageFileBadNameError(
                 "bad stage filename '{}'. Stage files should be named"
                 " 'Dvcfile' or have a '.dvc' suffix (e.g. '{}.dvc').".format(
-                    os.path.relpath(fname), os.path.basename(fname)
+                    relpath(fname), os.path.basename(fname)
                 )
             )
 
@@ -593,7 +594,7 @@ class Stage(object):
         # looses keys in deps and outs load
         state = copy.deepcopy(d)
 
-        Stage.validate(d, fname=os.path.relpath(fname))
+        Stage.validate(d, fname=relpath(fname))
         path = os.path.abspath(fname)
 
         stage = Stage(
@@ -617,7 +618,7 @@ class Stage(object):
         return stage
 
     def dumpd(self):
-        rel_wdir = os.path.relpath(self.wdir, os.path.dirname(self.path))
+        rel_wdir = relpath(self.wdir, os.path.dirname(self.path))
         return {
             key: value
             for key, value in {
@@ -638,15 +639,13 @@ class Stage(object):
         self._check_dvc_filename(fname)
 
         logger.info(
-            "Saving information to '{file}'.".format(
-                file=os.path.relpath(fname)
-            )
+            "Saving information to '{file}'.".format(file=relpath(fname))
         )
         d = self.dumpd()
         apply_diff(d, self._state)
         dump_stage_file(fname, self._state)
 
-        self.repo.scm.track_file(os.path.relpath(fname))
+        self.repo.scm.track_file(relpath(fname))
 
     def _compute_md5(self):
         from dvc.output.base import OutputBase

dvc/state.py

@@ -7,7 +7,7 @@ import sqlite3
 import logging
 
 from dvc.config import Config
-from dvc.utils import remove, current_timestamp
+from dvc.utils import remove, current_timestamp, relpath
 from dvc.exceptions import DvcException
 from dvc.utils.fs import get_mtime_and_size, get_inode
 from dvc.utils.compat import fspath_py35
@@ -416,12 +416,15 @@ class State(StateBase):  # pylint: disable=too-many-instance-attributes
 
         mtime, _ = get_mtime_and_size(path)
         inode = get_inode(path)
-        relpath = os.path.relpath(path, self.root_dir)
+        relative_path = relpath(path, self.root_dir)
 
         cmd = (
             "REPLACE INTO {}(path, inode, mtime) "
             'VALUES ("{}", {}, "{}")'.format(
-                self.LINK_STATE_TABLE, relpath, self._to_sqlite(inode), mtime
+                self.LINK_STATE_TABLE,
+                relative_path,
+                self._to_sqlite(inode),
+                mtime,
             )
         )
         self._execute(cmd)

dvc/utils/__init__.py

@@ -2,7 +2,14 @@
 
 from __future__ import unicode_literals
 
-from dvc.utils.compat import str, builtin_str, open, cast_bytes_py2, StringIO
+from dvc.utils.compat import (
+    str,
+    builtin_str,
+    open,
+    cast_bytes_py2,
+    StringIO,
+    fspath_py35,
+)
 from dvc.utils.compat import fspath
 
 import os
@@ -46,8 +53,8 @@ def file_md5(fname):
         if size >= LARGE_FILE_SIZE:
             bar = True
             msg = "Computing md5 for a large file {}. This is only done once."
-            logger.info(msg.format(os.path.relpath(fname)))
-            name = os.path.relpath(fname)
+            logger.info(msg.format(relpath(fname)))
+            name = relpath(fname)
             total = 0
 
         with open(fname, "rb") as fobj:
@@ -170,7 +177,7 @@ def _chmod(func, p, excinfo):
 
 
 def remove(path):
-    logger.debug("Removing '{}'".format(os.path.relpath(path)))
+    logger.debug("Removing '{}'".format(relpath(path)))
 
     try:
         if os.path.isdir(path):
@@ -369,3 +376,15 @@ def _visual_center(line, width):
     right_padding = spaces - left_padding
 
     return (left_padding * " ") + line + (right_padding * " ")
+
+
+def relpath(path, start=os.curdir):
+    path = fspath_py35(path)
+    start = fspath_py35(os.path.abspath(start))
+
+    # Windows path on different drive than curdir doesn't have relpath
+    if os.name == "nt" and not os.path.commonprefix(
+        [start, os.path.abspath(path)]
+    ):
+        return path
+    return os.path.relpath(path, start)

tests/basic_env.py

@@ -83,10 +83,12 @@ class TestDirFixture(object):
             )
 
     @staticmethod
-    def mkdtemp():
+    def mkdtemp(base_directory=None):
         prefix = "dvc-test.{}.".format(os.getpid())
         suffix = ".{}".format(uuid.uuid4())
-        return tempfile.mkdtemp(prefix=prefix, suffix=suffix)
+        return tempfile.mkdtemp(
+            prefix=prefix, suffix=suffix, dir=base_directory
+        )
 
     def setUp(self):
         self._pushd(self._root_dir)

tests/conftest.py

@@ -126,7 +126,9 @@ def temporary_windows_drive(repo_dir):
     if set_up_result == 0:
         raise RuntimeError("Failed to mount windows drive!")
 
-    yield new_drive
+    # NOTE: new_drive has form of `A:` and joining it with some relative
+    # path might result in non-existing path (A:path\\to)
+    yield os.path.join(new_drive, os.sep)
 
     tear_down_result = windll.kernel32.DefineDosDeviceW(
         DDD_REMOVE_DEFINITION, new_drive, target_path

tests/func/test_add.py

@@ -16,7 +16,7 @@ from dvc.system import System
 from mock import patch
 
 from dvc.main import main
-from dvc.utils import file_md5, LARGE_DIR_SIZE
+from dvc.utils import file_md5, LARGE_DIR_SIZE, relpath
 from dvc.utils.stage import load_stage_file
 from dvc.utils.compat import range
 from dvc.stage import Stage
@@ -421,7 +421,7 @@ class TestShouldThrowProperExceptionOnCorruptedStageFile(TestDvc):
         ret = main(["add", self.FOO])
         assert 0 == ret
 
-        foo_stage = os.path.relpath(self.FOO + Stage.STAGE_FILE_SUFFIX)
+        foo_stage = relpath(self.FOO + Stage.STAGE_FILE_SUFFIX)
 
         # corrupt stage file
         with open(foo_stage, "a+") as file:

tests/func/test_cache.py

@@ -4,6 +4,7 @@ import configobj
 
 from dvc.cache import Cache
 from dvc.main import main
+from dvc.utils import relpath
 
 from tests.basic_env import TestDvc, TestDir
 
@@ -152,7 +153,7 @@ class TestCmdCacheDir(TestDvc):
 
     def test_relative_path(self):
         tmpdir = self.mkdtemp()
-        dname = os.path.relpath(tmpdir)
+        dname = relpath(tmpdir)
         ret = main(["cache", "dir", dname])
         self.assertEqual(ret, 0)
 

tests/func/test_checkout.py

@@ -11,7 +11,7 @@ from dvc.main import main
 from dvc import progress
 from dvc.repo import Repo as DvcRepo
 from dvc.system import System
-from dvc.utils import walk_files
+from dvc.utils import walk_files, relpath
 from dvc.utils.stage import load_stage_file, dump_stage_file
 from tests.basic_env import TestDvc
 from tests.func.test_repro import TestRepro
@@ -566,11 +566,11 @@ class TestCheckoutMovedCacheDirWithSymlinks(TestDvc):
         new_data_link = readlink(self.DATA)
 
         self.assertEqual(
-            os.path.relpath(old_foo_link, old_cache_dir),
-            os.path.relpath(new_foo_link, new_cache_dir),
+            relpath(old_foo_link, old_cache_dir),
+            relpath(new_foo_link, new_cache_dir),
         )
 
         self.assertEqual(
-            os.path.relpath(old_data_link, old_cache_dir),
-            os.path.relpath(new_data_link, new_cache_dir),
+            relpath(old_data_link, old_cache_dir),
+            relpath(new_data_link, new_cache_dir),
         )

tests/func/test_metrics.py

@@ -10,6 +10,7 @@ from dvc.main import main
 from dvc.exceptions import DvcException, BadMetricError, NoMetricsError
 from dvc.repo.metrics.show import NO_METRICS_FILE_AT_REFERENCE_WARNING
 from dvc.stage import Stage
+from dvc.utils import relpath
 from tests.basic_env import TestDvc
 
 
@@ -342,7 +343,7 @@ class TestMetrics(TestMetricsBase):
         self.assertMetricsHaveRelativePaths(metrics)
 
     def assertMetricsHaveRelativePaths(self, metrics):
-        root_relpath = os.path.relpath(self.dvc.root_dir)
+        root_relpath = relpath(self.dvc.root_dir)
         metric_path = os.path.join(root_relpath, "metric")
         metric_json_path = os.path.join(root_relpath, "metric_json")
         metric_tsv_path = os.path.join(root_relpath, "metric_tsv")

tests/func/test_repro.py

@@ -18,7 +18,7 @@ import pytest
 
 from dvc.main import main
 from dvc.repo import Repo as DvcRepo
-from dvc.utils import file_md5
+from dvc.utils import file_md5, relpath
 from dvc.utils.stage import load_stage_file, dump_stage_file
 from dvc.remote.local import RemoteLOCAL
 from dvc.stage import Stage, StageFileDoesNotExistError
@@ -142,7 +142,7 @@ class TestReproWorkingDirectoryAsOutput(TestDvc):
         os.mkdir(dir2)
 
         nested_dir = os.path.join(dir2, "nested")
-        out_dir = os.path.relpath(nested_dir, dir1)
+        out_dir = relpath(nested_dir, dir1)
 
         nested_stage = self.dvc.run(
             cwd=dir1,  # b

tests/unit/utils/test_fs.py

@@ -4,6 +4,7 @@ from unittest import TestCase
 import dvc
 import pytest
 from dvc.system import System
+from dvc.utils import relpath
 from dvc.utils.compat import str
 from dvc.utils.fs import (
     get_mtime_and_size,
@@ -135,3 +136,11 @@ def test_get_parent_dirs_up_to(path1, path2, expected_dirs):
     result = get_parent_dirs_up_to(path1, path2)
 
     assert set(result) == set(expected_dirs)
+
+
+@pytest.mark.skipif(os.name != "nt", reason="Windows specific")
+def test_relpath_windows_different_drives():
+    path1 = os.path.join("A:", os.sep, "some", "path")
+    path2 = os.path.join("B:", os.sep, "other", "path")
+
+    assert relpath(path1, path2) == path1