Create ensure_dir helper.

We had a very widely used pattern which can be factored out for a mild
saving in LOC, and a gain in clarity.

pip/commands/install.py

@@ -16,6 +16,7 @@
     InstallationError, CommandError, PreviousBuildDirError,
 )
 from pip import cmdoptions
+from pip.utils import ensure_dir
 from pip.utils.build import BuildDirectory
 from pip.utils.deprecation import RemovedInPip7Warning, RemovedInPip8Warning
 
@@ -361,8 +362,7 @@ def run(self, options, args):
                         requirement_set.cleanup_files()
 
         if options.target_dir:
-            if not os.path.exists(options.target_dir):
-                os.makedirs(options.target_dir)
+            ensure_dir(options.target_dir)
 
             lib_dir = distutils_scheme('', home=temp_target_dir)['purelib']
 

pip/commands/zip.py

@@ -9,7 +9,7 @@
 import warnings
 import zipfile
 
-from pip.utils import display_path, backup_dir, rmtree
+from pip.utils import display_path, ensure_dir, backup_dir, rmtree
 from pip.utils.deprecation import RemovedInPip7Warning
 from pip.utils.logging import indent_log
 from pip.exceptions import InstallationError
@@ -183,11 +183,9 @@ def unzip_package(self, module_name, filename):
                 if name.startswith(module_name + os.path.sep):
                     content = zip.read(name)
                     dest = os.path.join(package_path, name)
-                    if not os.path.exists(os.path.dirname(dest)):
-                        os.makedirs(os.path.dirname(dest))
+                    ensure_dir(os.path.dirname(dest))
                     if not content and dest.endswith(os.path.sep):
-                        if not os.path.exists(dest):
-                            os.makedirs(dest)
+                        ensure_dir(os.path.dirname(dest))
                     else:
                         with open(dest, 'wb') as f:
                             f.write(content)

pip/req/req_install.py

@@ -31,7 +31,7 @@
 from pip.utils import (
     display_path, rmtree, ask_path_exists, backup_dir, is_installable_dir,
     dist_in_usersite, dist_in_site_packages, egg_link_path, make_path_relative,
-    call_subprocess, read_text_file, FakeFile, _make_build_dir,
+    call_subprocess, read_text_file, FakeFile, _make_build_dir, ensure_dir,
 )
 from pip.utils.deprecation import RemovedInPip8Warning
 from pip.utils.logging import indent_log
@@ -391,8 +391,7 @@ def run_egg_info(self):
                 egg_base_option = []
             else:
                 egg_info_dir = os.path.join(self.source_dir, 'pip-egg-info')
-                if not os.path.exists(egg_info_dir):
-                    os.makedirs(egg_info_dir)
+                ensure_dir(egg_info_dir)
                 egg_base_option = ['--egg-base', 'pip-egg-info']
             cwd = self.source_dir
             if self.editable_options and \

pip/req/req_set.py

@@ -14,7 +14,8 @@
                             DistributionNotFound, PreviousBuildDirError)
 from pip.locations import (PIP_DELETE_MARKER_FILENAME, build_prefix)
 from pip.req.req_install import InstallRequirement
-from pip.utils import (display_path, rmtree, dist_in_usersite, normalize_path)
+from pip.utils import (
+    ensure_dir, display_path, rmtree, dist_in_usersite, normalize_path)
 from pip.utils.logging import indent_log
 from pip.vcs import vcs
 
@@ -343,8 +344,7 @@ def prepare_files(self, finder):
         """
         # make the wheelhouse
         if self.wheel_download_dir:
-            if not os.path.exists(self.wheel_download_dir):
-                os.makedirs(self.wheel_download_dir)
+            ensure_dir(self.wheel_download_dir)
 
         self._walk_req_to_install(
             functools.partial(self._prepare_file, finder))

pip/utils/__init__.py

@@ -1,6 +1,7 @@
 from __future__ import absolute_import
 
 import contextlib
+import errno
 import locale
 import logging
 import re
@@ -38,7 +39,7 @@
            'make_path_relative', 'normalize_path',
            'renames', 'get_terminal_size', 'get_prog',
            'unzip_file', 'untar_file', 'unpack_file', 'call_subprocess',
-           'captured_stdout', 'remove_tracebacks']
+           'captured_stdout', 'remove_tracebacks', 'ensure_dir']
 
 
 logger = logging.getLogger(__name__)
@@ -51,6 +52,17 @@ def import_or_raise(pkg_or_module_string, ExceptionType, *args, **kwargs):
         raise ExceptionType(*args, **kwargs)
 
 
+def ensure_dir(path):
+    """os.path.makedirs without EEXIST."""
+    try:
+        os.makedirs(path)
+    except OSError as e:
+        if e.errno == errno.EEXIST:
+            pass
+        else:
+            raise
+
+
 def get_prog():
     try:
         if os.path.basename(sys.argv[0]) in ('__main__.py', '-c'):
@@ -502,8 +514,7 @@ def unzip_file(filename, location, flatten=True):
     written. Note that for windows, any execute changes using os.chmod are
     no-ops per the python docs.
     """
-    if not os.path.exists(location):
-        os.makedirs(location)
+    ensure_dir(location)
     zipfp = open(filename, 'rb')
     try:
         zip = zipfile.ZipFile(zipfp, allowZip64=True)
@@ -516,13 +527,11 @@ def unzip_file(filename, location, flatten=True):
                 fn = split_leading_dir(name)[1]
             fn = os.path.join(location, fn)
             dir = os.path.dirname(fn)
-            if not os.path.exists(dir):
-                os.makedirs(dir)
             if fn.endswith('/') or fn.endswith('\\'):
                 # A directory
-                if not os.path.exists(fn):
-                    os.makedirs(fn)
+                ensure_dir(fn)
             else:
+                ensure_dir(dir)
                 fp = open(fn, 'wb')
                 try:
                     fp.write(data)
@@ -548,8 +557,7 @@ def untar_file(filename, location):
     written.  Note that for windows, any execute changes using os.chmod are
     no-ops per the python docs.
     """
-    if not os.path.exists(location):
-        os.makedirs(location)
+    ensure_dir(location)
     if filename.lower().endswith('.gz') or filename.lower().endswith('.tgz'):
         mode = 'r:gz'
     elif (filename.lower().endswith('.bz2') or
@@ -577,8 +585,7 @@ def untar_file(filename, location):
                 fn = split_leading_dir(fn)[1]
             path = os.path.join(location, fn)
             if member.isdir():
-                if not os.path.exists(path):
-                    os.makedirs(path)
+                ensure_dir(path)
             elif member.issym():
                 try:
                     tar._extract_member(member, path)
@@ -601,8 +608,7 @@ def untar_file(filename, location):
                         filename, member.name, exc,
                     )
                     continue
-                if not os.path.exists(os.path.dirname(path)):
-                    os.makedirs(os.path.dirname(path))
+                ensure_dir(os.path.dirname(path))
                 destfp = open(path, 'wb')
                 try:
                     shutil.copyfileobj(fp, destfp)

pip/utils/logging.py

@@ -11,6 +11,7 @@
     import dummy_threading as threading
 
 from pip.compat import WINDOWS
+from pip.utils import ensure_dir
 
 try:
     from pip._vendor import colorama
@@ -114,8 +115,5 @@ def format(self, record):
 class BetterRotatingFileHandler(logging.handlers.RotatingFileHandler):
 
     def _open(self):
-        # Ensure the directory exists
-        if not os.path.exists(os.path.dirname(self.baseFilename)):
-            os.makedirs(os.path.dirname(self.baseFilename))
-
+        ensure_dir(os.path.dirname(self.baseFilename))
         return logging.handlers.RotatingFileHandler._open(self)

pip/utils/outdated.py

@@ -1,7 +1,6 @@
 from __future__ import absolute_import
 
 import datetime
-import errno
 import json
 import logging
 import os.path
@@ -13,6 +12,7 @@
 from pip.compat import total_seconds
 from pip.index import PyPI
 from pip.locations import USER_CACHE_DIR, running_under_virtualenv
+from pip.utils import ensure_dir
 from pip.utils.filesystem import check_path_owner
 
 
@@ -65,11 +65,7 @@ def save(self, pypi_version, current_time):
 
         # Now that we've ensured the directory is owned by this user, we'll go
         # ahead and make sure that all our directories are created.
-        try:
-            os.makedirs(os.path.dirname(self.statefile_path))
-        except OSError as exc:
-            if exc.errno != errno.EEXIST:
-                raise
+        ensure_dir(self.statefile_path)
 
         # Attempt to write out our version check file
         with lockfile.LockFile(self.statefile_path):

pip/wheel.py

@@ -23,7 +23,8 @@
 from pip.exceptions import InvalidWheelFilename, UnsupportedWheel
 from pip.locations import distutils_scheme
 from pip import pep425tags
-from pip.utils import call_subprocess, make_path_relative, captured_stdout
+from pip.utils import (
+    call_subprocess, ensure_dir, make_path_relative, captured_stdout)
 from pip.utils.logging import indent_log
 from pip._vendor.distlib.scripts import ScriptMaker
 from pip._vendor import pkg_resources
@@ -174,8 +175,7 @@ def record_installed(srcfile, destfile, modified=False):
             changed.add(destfile)
 
     def clobber(source, dest, is_base, fixer=None, filter=None):
-        if not os.path.exists(dest):  # common for the 'include' path
-            os.makedirs(dest)
+        ensure_dir(dest)  # common for the 'include' path
 
         for dir, subdirs, files in os.walk(source):
             basedir = dir[len(source):].lstrip(os.path.sep)
@@ -203,8 +203,7 @@ def clobber(source, dest, is_base, fixer=None, filter=None):
                 # directory creation is lazy and after the file filtering above
                 # to ensure we don't install empty dirs; empty dirs can't be
                 # uninstalled.
-                if not os.path.exists(destdir):
-                    os.makedirs(destdir)
+                ensure_dir(destdir)
 
                 # We use copyfile (not move, copy, or copy2) to be extra sure
                 # that we are not moving directories over (copyfile fails for