--- a/python/mozbuild/mozbuild/vendor/mach_commands.py
+++ b/python/mozbuild/mozbuild/vendor/mach_commands.py
@@ -144,25 +144,32 @@ Please commit or stash these changes bef
         vendor_command = self._spawn(VendorRust)
         vendor_command.vendor(**kwargs)
 
     # =====================================================================
 
     @SubCommand(
         "vendor",
         "python",
-        description="Vendor Python packages from pypi.org into third_party/python",
+        description="Vendor Python packages from pypi.org into third_party/python. "
+                    "Some extra files like docs and tests will automatically be excluded.",
     )
     @CommandArgument(
         "--with-windows-wheel",
         action="store_true",
         help="Vendor a wheel for Windows along with the source package",
         default=False,
     )
     @CommandArgument(
+        "--keep-extra-files",
+        action="store_true",
+        default=False,
+        help="Keep all files, including tests and documentation.",
+    )
+    @CommandArgument(
         "packages",
         default=None,
         nargs="*",
         help="Packages to vendor. If omitted, packages and their dependencies "
         "defined in Pipfile.lock will be vendored. If Pipfile has been modified, "
         "then Pipfile.lock will be regenerated. Note that transient dependencies "
         "may be updated when running this command.",
     )

--- a/python/mozbuild/mozbuild/vendor/vendor_python.py
+++ b/python/mozbuild/mozbuild/vendor/vendor_python.py
@@ -11,17 +11,17 @@ import subprocess
 import mozfile
 import mozpack.path as mozpath
 from mozbuild.base import MozbuildObject
 from mozfile import TemporaryDirectory
 from mozpack.files import FileFinder
 
 
 class VendorPython(MozbuildObject):
-    def vendor(self, packages=None, with_windows_wheel=False):
+    def vendor(self, packages=None, with_windows_wheel=False, keep_extra_files=False):
         self.populate_logger()
         self.log_manager.enable_unstructured()
 
         vendor_dir = mozpath.join(self.topsrcdir, os.path.join("third_party", "python"))
 
         packages = packages or []
         if with_windows_wheel and len(packages) != 1:
             raise Exception(
@@ -94,17 +94,17 @@ class VendorPython(MozbuildObject):
                             "--python-version",
                             "27",
                             "--abi",
                             "none",
                             "--disable-pip-version-check",
                             packages[0],
                         ]
                     )
-                self._extract(tmp, vendor_dir)
+                self._extract(tmp, vendor_dir, keep_extra_files)
 
             shutil.copyfile(tmpspec_absolute, spec)
             self.repository.add_remove_files(vendor_dir)
 
     def _update_packages(self, spec, packages):
         for package in packages:
             if not all(package.partition("==")):
                 raise Exception(
@@ -128,37 +128,46 @@ class VendorPython(MozbuildObject):
             requirements[name] = version, []
 
         with open(spec, "w") as f:
             for name, (version, comments) in sorted(requirements.items()):
                 if comments:
                     f.write("{}\n".format("\n".join(comments)))
                 f.write("{}=={}\n".format(name, version))
 
-    def _extract(self, src, dest):
+    def _extract(self, src, dest, keep_extra_files=False):
         """extract source distribution into vendor directory"""
+
+        ignore = ()
+        if not keep_extra_files:
+            ignore = (
+                '*/doc',
+                '*/docs',
+                '*/test',
+                '*/tests',
+            )
         finder = FileFinder(src)
         for path, _ in finder.find("*"):
             base, ext = os.path.splitext(path)
             if ext == ".whl":
                 # Wheels would extract into a directory with the name of the package, but
                 # we want the platform signifiers, minus the version number.
                 # Wheel filenames look like:
                 # {distribution}-{version}(-{build tag})?-{python tag}-{abi tag}-{platform tag}
                 bits = base.split("-")
 
                 # Remove the version number.
                 bits.pop(1)
                 target = os.path.join(dest, "-".join(bits))
                 mozfile.remove(target)  # remove existing version of vendored package
                 os.mkdir(target)
-                mozfile.extract(os.path.join(finder.base, path), target)
+                mozfile.extract(os.path.join(finder.base, path), target, ignore=ignore)
             else:
                 # packages extract into package-version directory name and we strip the version
-                tld = mozfile.extract(os.path.join(finder.base, path), dest)[0]
+                tld = mozfile.extract(os.path.join(finder.base, path), dest, ignore=ignore)[0]
                 target = os.path.join(dest, tld.rpartition("-")[0])
                 mozfile.remove(target)  # remove existing version of vendored package
                 mozfile.move(tld, target)
             # If any files inside the vendored package were symlinks, turn them into normal files
             # because hg.mozilla.org forbids symlinks in the repository.
             link_finder = FileFinder(target)
             for _, f in link_finder.find("**"):
                 if os.path.islink(f.path):