capybara/virtualenv/lib/python2.7/site-packages/wheel/install.py
def install(self, force=False, overrides={}):
        """
        Install the wheel into site-packages.
        """

        # Utility to get the target directory for a particular key
        def get_path(key):
            return overrides.get(key) or self.install_paths[key]

        # The base target location is either purelib or platlib
        if self.parsed_wheel_info['Root-Is-Purelib'] == 'true':
            root = get_path('purelib')
        else:
            root = get_path('platlib')

        # Parse all the names in the archive
        name_trans = {}
        for info in self.zipfile.infolist():
            name = info.filename
            # Zip files can contain entries representing directories.
            # These end in a '/'.
            # We ignore these, as we create directories on demand.
            if name.endswith('/'):
                continue

            # Pathnames in a zipfile namelist are always /-separated.
            # In theory, paths could start with ./ or have other oddities
            # but this won't happen in practical cases of well-formed wheels.
            # We'll cover the simple case of an initial './' as it's both easy
            # to do and more common than most other oddities.
            if name.startswith('./'):
                name = name[2:]

            # Split off the base directory to identify files that are to be
            # installed in non-root locations
            basedir, sep, filename = name.partition('/')
            if sep and basedir == self.datadir_name:
                # Data file. Target destination is elsewhere
                key, sep, filename = filename.partition('/')
                if not sep:
                    raise ValueError("Invalid filename in wheel: {0}".format(name))
                target = get_path(key)
            else:
                # Normal file. Target destination is root
                key = ''
                target = root
                filename = name

            # Map the actual filename from the zipfile to its intended target
            # directory and the pathname relative to that directory.
            dest = os.path.normpath(os.path.join(target, filename))
            name_trans[info] = (key, target, filename, dest)

        # We're now ready to start processing the actual install. The process
        # is as follows:
        #   1. Prechecks - is the wheel valid, is its declared architecture
        #      OK, etc. [[Responsibility of the caller]]
        #   2. Overwrite check - do any of the files to be installed already
        #      exist?
        #   3. Actual install - put the files in their target locations.
        #   4. Update RECORD - write a suitably modified RECORD file to
        #      reflect the actual installed paths.

        if not force:
            for info, v in name_trans.items():
                k = info.filename
                key, target, filename, dest = v
                if os.path.exists(dest):
                    raise ValueError("Wheel file {0} would overwrite {1}. Use force if this is intended".format(k, dest))

        # Get the name of our executable, for use when replacing script
        # wrapper hashbang lines.
        # We encode it using getfilesystemencoding, as that is "the name of
        # the encoding used to convert Unicode filenames into system file
        # names".
        exename = sys.executable.encode(sys.getfilesystemencoding())
        record_data = []
        record_name = self.distinfo_name + '/RECORD'
        for info, (key, target, filename, dest) in name_trans.items():
            name = info.filename
            source = self.zipfile.open(info)
            # Skip the RECORD file
            if name == record_name:
                continue
            ddir = os.path.dirname(dest)
            if not os.path.isdir(ddir):
                os.makedirs(ddir)
            destination = HashingFile(open(dest, 'wb'))
            if key == 'scripts':
                hashbang = source.readline()
                if hashbang.startswith(b'#!python'):
                    hashbang = b'#!' + exename + binary(os.linesep)
                destination.write(hashbang)
            shutil.copyfileobj(source, destination)
            reldest = os.path.relpath(dest, root)
            reldest.replace(os.sep, '/')
            record_data.append((reldest, destination.digest(), destination.length))
            destination.close()
            source.close()
            # preserve attributes (especially +x bit for scripts)
            attrs = info.external_attr >> 16
            if attrs:  # tends to be 0 if Windows.
                os.chmod(dest, info.external_attr >> 16)

        record_name = os.path.join(root, self.record_name)
        writer = csv.writer(open_for_csv(record_name, 'w+'))
        for reldest, digest, length in sorted(record_data):
            writer.writerow((reldest, digest, length))
        writer.writerow((self.record_name, '', ''))
def install(self, force=False, overrides={}):
        """
        Install the wheel into site-packages.
        """

        # Utility to get the target directory for a particular key
        def get_path(key):
            return overrides.get(key) or self.install_paths[key]

        # The base target location is either purelib or platlib
        if self.parsed_wheel_info['Root-Is-Purelib'] == 'true':
            root = get_path('purelib')
        else:
            root = get_path('platlib')

        # Parse all the names in the archive
        name_trans = {}
        for info in self.zipfile.infolist():
            name = info.filename
            # Zip files can contain entries representing directories.
            # These end in a '/'.
            # We ignore these, as we create directories on demand.
            if name.endswith('/'):
                continue

            # Pathnames in a zipfile namelist are always /-separated.
            # In theory, paths could start with ./ or have other oddities
            # but this won't happen in practical cases of well-formed wheels.
            # We'll cover the simple case of an initial './' as it's both easy
            # to do and more common than most other oddities.
            if name.startswith('./'):
                name = name[2:]

            # Split off the base directory to identify files that are to be
            # installed in non-root locations
            basedir, sep, filename = name.partition('/')
            if sep and basedir == self.datadir_name:
                # Data file. Target destination is elsewhere
                key, sep, filename = filename.partition('/')
                if not sep:
                    raise ValueError("Invalid filename in wheel: {0}".format(name))
                target = get_path(key)
            else:
                # Normal file. Target destination is root
                key = ''
                target = root
                filename = name

            # Map the actual filename from the zipfile to its intended target
            # directory and the pathname relative to that directory.
            dest = os.path.normpath(os.path.join(target, filename))
            name_trans[info] = (key, target, filename, dest)

        # We're now ready to start processing the actual install. The process
        # is as follows:
        #   1. Prechecks - is the wheel valid, is its declared architecture
        #      OK, etc. [[Responsibility of the caller]]
        #   2. Overwrite check - do any of the files to be installed already
        #      exist?
        #   3. Actual install - put the files in their target locations.
        #   4. Update RECORD - write a suitably modified RECORD file to
        #      reflect the actual installed paths.

        if not force:
            for info, v in name_trans.items():
                k = info.filename
                key, target, filename, dest = v
                if os.path.exists(dest):
                    raise ValueError("Wheel file {0} would overwrite {1}. Use force if this is intended".format(k, dest))

        # Get the name of our executable, for use when replacing script
        # wrapper hashbang lines.
        # We encode it using getfilesystemencoding, as that is "the name of
        # the encoding used to convert Unicode filenames into system file
        # names".
        exename = sys.executable.encode(sys.getfilesystemencoding())
        record_data = []
        record_name = self.distinfo_name + '/RECORD'
        for info, (key, target, filename, dest) in name_trans.items():
            name = info.filename
            source = self.zipfile.open(info)
            # Skip the RECORD file
            if name == record_name:
                continue
            ddir = os.path.dirname(dest)
            if not os.path.isdir(ddir):
                os.makedirs(ddir)
            destination = HashingFile(open(dest, 'wb'))
            if key == 'scripts':
                hashbang = source.readline()
                if hashbang.startswith(b'#!python'):
                    hashbang = b'#!' + exename + binary(os.linesep)
                destination.write(hashbang)
            shutil.copyfileobj(source, destination)
            reldest = os.path.relpath(dest, root)
            reldest.replace(os.sep, '/')
            record_data.append((reldest, destination.digest(), destination.length))
            destination.close()
            source.close()
            # preserve attributes (especially +x bit for scripts)
            attrs = info.external_attr >> 16
            if attrs:  # tends to be 0 if Windows.
                os.chmod(dest, info.external_attr >> 16)

        record_name = os.path.join(root, self.record_name)
        writer = csv.writer(open_for_csv(record_name, 'w+'))
        for reldest, digest, length in sorted(record_data):
            writer.writerow((reldest, digest, length))
        writer.writerow((self.record_name, '', ''))
Install the wheel into site-packages.