Python pip.wheel 模块，filename() 实例源码

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def read_text_file(filename):
    """Return the contents of *filename*.

    Try to decode the file contents with utf-8, the preffered system encoding
    (e.g., cp1252 on some Windows machines) and latin1, in that order. Decoding
    a byte string with latin1 will never raise an error. In the worst case, the
    returned string will contain some garbage characters.

    """
    with open(filename, 'rb') as fp:
        data = fp.read()

    encodings = ['utf-8', locale.getpreferredencoding(False), 'latin1']
    for enc in encodings:
        try:
            data = data.decode(enc)
        except UnicodeDecodeError:
            continue
        break

    assert type(data) != bytes  # Latin1 should have worked.
    return data

def from_line(cls, name, comes_from=None, prereleases=None):
        """Creates an InstallRequirement from a name, which might be a
        requirement, directory containing 'setup.py', filename, or URL.
        """
        url = None
        name = name.strip()
        req = None
        path = os.path.normpath(os.path.abspath(name))
        link = None

        if is_url(name):
            link = Link(name)
        elif os.path.isdir(path) and (os.path.sep in name or name.startswith('.')):
            if not is_installable_dir(path):
                raise InstallationError("Directory %r is not installable. File 'setup.py' not found." % name)
            link = Link(path_to_url(name))
        elif is_archive_file(path):
            if not os.path.isfile(path):
                logger.warn('Requirement %r looks like a filename, but the file does not exist', name)
            link = Link(path_to_url(name))

        # If the line has an egg= definition, but isn't editable, pull the requirement out.
        # Otherwise, assume the name is the req for the non URL/path/archive case.
        if link and req is None:
            url = link.url_without_fragment
            req = link.egg_fragment  #when fragment is None, this will become an 'unnamed' requirement

            # Handle relative file URLs
            if link.scheme == 'file' and re.search(r'\.\./', url):
                url = path_to_url(os.path.normpath(os.path.abspath(link.path)))

            # fail early for invalid or unsupported wheels
            if link.ext == wheel_ext:
                wheel = Wheel(link.filename) # can raise InvalidWheelFilename
                if not wheel.supported():
                    raise UnsupportedWheel("%s is not a supported wheel on this platform." % wheel.filename)

        else:
            req = name

        return cls(req, comes_from, url=url, prereleases=prereleases)

def egg_info_data(self, filename):
        if self.satisfied_by is not None:
            if not self.satisfied_by.has_metadata(filename):
                return None
            return self.satisfied_by.get_metadata(filename)
        assert self.source_dir
        filename = self.egg_info_path(filename)
        if not os.path.exists(filename):
            return None
        data = read_text_file(filename)
        return data

def egg_info_path(self, filename):
        if self._egg_info_path is None:
            if self.editable:
                base = self.source_dir
            else:
                base = os.path.join(self.source_dir, 'pip-egg-info')
            filenames = os.listdir(base)
            if self.editable:
                filenames = []
                for root, dirs, files in os.walk(base):
                    for dir in vcs.dirnames:
                        if dir in dirs:
                            dirs.remove(dir)
                    # Iterate over a copy of ``dirs``, since mutating
                    # a list while iterating over it can cause trouble.
                    # (See https://github.com/pypa/pip/pull/462.)
                    for dir in list(dirs):
                        # Don't search in anything that looks like a virtualenv environment
                        if (os.path.exists(os.path.join(root, dir, 'bin', 'python'))
                            or os.path.exists(os.path.join(root, dir, 'Scripts', 'Python.exe'))):
                            dirs.remove(dir)
                        # Also don't search through tests
                        if dir == 'test' or dir == 'tests':
                            dirs.remove(dir)
                    filenames.extend([os.path.join(root, dir)
                                     for dir in dirs])
                filenames = [f for f in filenames if f.endswith('.egg-info')]

            if not filenames:
                raise InstallationError('No files/directories in %s (from %s)' % (base, filename))
            assert filenames, "No files/directories in %s (from %s)" % (base, filename)

            # if we have more than one match, we pick the toplevel one.  This can
            # easily be the case if there is a dist folder which contains an
            # extracted tarball for testing purposes.
            if len(filenames) > 1:
                filenames.sort(key=lambda x: x.count(os.path.sep) +
                                             (os.path.altsep and
                                              x.count(os.path.altsep) or 0))
            self._egg_info_path = os.path.join(base, filenames[0])
        return os.path.join(self._egg_info_path, filename)

def egg_info_lines(self, filename):
        data = self.egg_info_data(filename)
        if not data:
            return []
        result = []
        for line in data.splitlines():
            line = line.strip()
            if not line or line.startswith('#'):
                continue
            result.append(line)
        return result

def egg_info_data(self, filename):
        if self.satisfied_by is not None:
            if not self.satisfied_by.has_metadata(filename):
                return None
            return self.satisfied_by.get_metadata(filename)
        assert self.source_dir
        filename = self.egg_info_path(filename)
        if not os.path.exists(filename):
            return None
        data = read_text_file(filename)
        return data

def from_line(cls, name, comes_from=None, prereleases=None):
        """Creates an InstallRequirement from a name, which might be a
        requirement, directory containing 'setup.py', filename, or URL.
        """
        url = None
        name = name.strip()
        req = None
        path = os.path.normpath(os.path.abspath(name))
        link = None

        if is_url(name):
            link = Link(name)
        elif os.path.isdir(path) and (os.path.sep in name or name.startswith('.')):
            if not is_installable_dir(path):
                raise InstallationError("Directory %r is not installable. File 'setup.py' not found." % name)
            link = Link(path_to_url(name))
        elif is_archive_file(path):
            if not os.path.isfile(path):
                logger.warn('Requirement %r looks like a filename, but the file does not exist', name)
            link = Link(path_to_url(name))

        # If the line has an egg= definition, but isn't editable, pull the requirement out.
        # Otherwise, assume the name is the req for the non URL/path/archive case.
        if link and req is None:
            url = link.url_without_fragment
            req = link.egg_fragment  #when fragment is None, this will become an 'unnamed' requirement

            # Handle relative file URLs
            if link.scheme == 'file' and re.search(r'\.\./', url):
                url = path_to_url(os.path.normpath(os.path.abspath(link.path)))

            # fail early for invalid or unsupported wheels
            if link.ext == wheel_ext:
                wheel = Wheel(link.filename) # can raise InvalidWheelFilename
                if not wheel.supported():
                    raise UnsupportedWheel("%s is not a supported wheel on this platform." % wheel.filename)

        else:
            req = name

        return cls(req, comes_from, url=url, prereleases=prereleases)

def egg_info_data(self, filename):
        if self.satisfied_by is not None:
            if not self.satisfied_by.has_metadata(filename):
                return None
            return self.satisfied_by.get_metadata(filename)
        assert self.source_dir
        filename = self.egg_info_path(filename)
        if not os.path.exists(filename):
            return None
        data = read_text_file(filename)
        return data

def egg_info_path(self, filename):
        if self._egg_info_path is None:
            if self.editable:
                base = self.source_dir
            else:
                base = os.path.join(self.source_dir, 'pip-egg-info')
            filenames = os.listdir(base)
            if self.editable:
                filenames = []
                for root, dirs, files in os.walk(base):
                    for dir in vcs.dirnames:
                        if dir in dirs:
                            dirs.remove(dir)
                    # Iterate over a copy of ``dirs``, since mutating
                    # a list while iterating over it can cause trouble.
                    # (See https://github.com/pypa/pip/pull/462.)
                    for dir in list(dirs):
                        # Don't search in anything that looks like a virtualenv environment
                        if (os.path.exists(os.path.join(root, dir, 'bin', 'python'))
                            or os.path.exists(os.path.join(root, dir, 'Scripts', 'Python.exe'))):
                            dirs.remove(dir)
                        # Also don't search through tests
                        if dir == 'test' or dir == 'tests':
                            dirs.remove(dir)
                    filenames.extend([os.path.join(root, dir)
                                     for dir in dirs])
                filenames = [f for f in filenames if f.endswith('.egg-info')]

            if not filenames:
                raise InstallationError('No files/directories in %s (from %s)' % (base, filename))
            assert filenames, "No files/directories in %s (from %s)" % (base, filename)

            # if we have more than one match, we pick the toplevel one.  This can
            # easily be the case if there is a dist folder which contains an
            # extracted tarball for testing purposes.
            if len(filenames) > 1:
                filenames.sort(key=lambda x: x.count(os.path.sep) +
                                             (os.path.altsep and
                                              x.count(os.path.altsep) or 0))
            self._egg_info_path = os.path.join(base, filenames[0])
        return os.path.join(self._egg_info_path, filename)

def egg_info_lines(self, filename):
        data = self.egg_info_data(filename)
        if not data:
            return []
        result = []
        for line in data.splitlines():
            line = line.strip()
            if not line or line.startswith('#'):
                continue
            result.append(line)
        return result

def egg_info_data(self, filename):
        if self.satisfied_by is not None:
            if not self.satisfied_by.has_metadata(filename):
                return None
            return self.satisfied_by.get_metadata(filename)
        assert self.source_dir
        filename = self.egg_info_path(filename)
        if not os.path.exists(filename):
            return None
        data = read_text_file(filename)
        return data

def from_line(cls, name, comes_from=None, prereleases=None):
        """Creates an InstallRequirement from a name, which might be a
        requirement, directory containing 'setup.py', filename, or URL.
        """
        url = None
        name = name.strip()
        req = None
        path = os.path.normpath(os.path.abspath(name))
        link = None

        if is_url(name):
            link = Link(name)
        elif os.path.isdir(path) and (os.path.sep in name or name.startswith('.')):
            if not is_installable_dir(path):
                raise InstallationError("Directory %r is not installable. File 'setup.py' not found." % name)
            link = Link(path_to_url(name))
        elif is_archive_file(path):
            if not os.path.isfile(path):
                logger.warn('Requirement %r looks like a filename, but the file does not exist', name)
            link = Link(path_to_url(name))

        # If the line has an egg= definition, but isn't editable, pull the requirement out.
        # Otherwise, assume the name is the req for the non URL/path/archive case.
        if link and req is None:
            url = link.url_without_fragment
            req = link.egg_fragment  #when fragment is None, this will become an 'unnamed' requirement

            # Handle relative file URLs
            if link.scheme == 'file' and re.search(r'\.\./', url):
                url = path_to_url(os.path.normpath(os.path.abspath(link.path)))

            # fail early for invalid or unsupported wheels
            if link.ext == wheel_ext:
                wheel = Wheel(link.filename) # can raise InvalidWheelFilename
                if not wheel.supported():
                    raise UnsupportedWheel("%s is not a supported wheel on this platform." % wheel.filename)

        else:
            req = name

        return cls(req, comes_from, url=url, prereleases=prereleases)

def egg_info_data(self, filename):
        if self.satisfied_by is not None:
            if not self.satisfied_by.has_metadata(filename):
                return None
            return self.satisfied_by.get_metadata(filename)
        assert self.source_dir
        filename = self.egg_info_path(filename)
        if not os.path.exists(filename):
            return None
        data = read_text_file(filename)
        return data

def egg_info_path(self, filename):
        if self._egg_info_path is None:
            if self.editable:
                base = self.source_dir
            else:
                base = os.path.join(self.source_dir, 'pip-egg-info')
            filenames = os.listdir(base)
            if self.editable:
                filenames = []
                for root, dirs, files in os.walk(base):
                    for dir in vcs.dirnames:
                        if dir in dirs:
                            dirs.remove(dir)
                    # Iterate over a copy of ``dirs``, since mutating
                    # a list while iterating over it can cause trouble.
                    # (See https://github.com/pypa/pip/pull/462.)
                    for dir in list(dirs):
                        # Don't search in anything that looks like a virtualenv environment
                        if (os.path.exists(os.path.join(root, dir, 'bin', 'python'))
                            or os.path.exists(os.path.join(root, dir, 'Scripts', 'Python.exe'))):
                            dirs.remove(dir)
                        # Also don't search through tests
                        if dir == 'test' or dir == 'tests':
                            dirs.remove(dir)
                    filenames.extend([os.path.join(root, dir)
                                     for dir in dirs])
                filenames = [f for f in filenames if f.endswith('.egg-info')]

            if not filenames:
                raise InstallationError('No files/directories in %s (from %s)' % (base, filename))
            assert filenames, "No files/directories in %s (from %s)" % (base, filename)

            # if we have more than one match, we pick the toplevel one.  This can
            # easily be the case if there is a dist folder which contains an
            # extracted tarball for testing purposes.
            if len(filenames) > 1:
                filenames.sort(key=lambda x: x.count(os.path.sep) +
                                             (os.path.altsep and
                                              x.count(os.path.altsep) or 0))
            self._egg_info_path = os.path.join(base, filenames[0])
        return os.path.join(self._egg_info_path, filename)

def egg_info_lines(self, filename):
        data = self.egg_info_data(filename)
        if not data:
            return []
        result = []
        for line in data.splitlines():
            line = line.strip()
            if not line or line.startswith('#'):
                continue
            result.append(line)
        return result

def from_line(cls, name, comes_from=None, prereleases=None):
        """Creates an InstallRequirement from a name, which might be a
        requirement, directory containing 'setup.py', filename, or URL.
        """
        url = None
        name = name.strip()
        req = None
        path = os.path.normpath(os.path.abspath(name))
        link = None

        if is_url(name):
            link = Link(name)
        elif os.path.isdir(path) and (os.path.sep in name or name.startswith('.')):
            if not is_installable_dir(path):
                raise InstallationError("Directory %r is not installable. File 'setup.py' not found." % name)
            link = Link(path_to_url(name))
        elif is_archive_file(path):
            if not os.path.isfile(path):
                logger.warn('Requirement %r looks like a filename, but the file does not exist', name)
            link = Link(path_to_url(name))

        # If the line has an egg= definition, but isn't editable, pull the requirement out.
        # Otherwise, assume the name is the req for the non URL/path/archive case.
        if link and req is None:
            url = link.url_without_fragment
            req = link.egg_fragment  #when fragment is None, this will become an 'unnamed' requirement

            # Handle relative file URLs
            if link.scheme == 'file' and re.search(r'\.\./', url):
                url = path_to_url(os.path.normpath(os.path.abspath(link.path)))

            # fail early for invalid or unsupported wheels
            if link.ext == wheel_ext:
                wheel = Wheel(link.filename) # can raise InvalidWheelFilename
                if not wheel.supported():
                    raise UnsupportedWheel("%s is not a supported wheel on this platform." % wheel.filename)

        else:
            req = name

        return cls(req, comes_from, url=url, prereleases=prereleases)

def egg_info_data(self, filename):
        if self.satisfied_by is not None:
            if not self.satisfied_by.has_metadata(filename):
                return None
            return self.satisfied_by.get_metadata(filename)
        assert self.source_dir
        filename = self.egg_info_path(filename)
        if not os.path.exists(filename):
            return None
        data = read_text_file(filename)
        return data

def egg_info_path(self, filename):
        if self._egg_info_path is None:
            if self.editable:
                base = self.source_dir
            else:
                base = os.path.join(self.source_dir, 'pip-egg-info')
            filenames = os.listdir(base)
            if self.editable:
                filenames = []
                for root, dirs, files in os.walk(base):
                    for dir in vcs.dirnames:
                        if dir in dirs:
                            dirs.remove(dir)
                    # Iterate over a copy of ``dirs``, since mutating
                    # a list while iterating over it can cause trouble.
                    # (See https://github.com/pypa/pip/pull/462.)
                    for dir in list(dirs):
                        # Don't search in anything that looks like a virtualenv environment
                        if (os.path.exists(os.path.join(root, dir, 'bin', 'python'))
                            or os.path.exists(os.path.join(root, dir, 'Scripts', 'Python.exe'))):
                            dirs.remove(dir)
                        # Also don't search through tests
                        if dir == 'test' or dir == 'tests':
                            dirs.remove(dir)
                    filenames.extend([os.path.join(root, dir)
                                     for dir in dirs])
                filenames = [f for f in filenames if f.endswith('.egg-info')]

            if not filenames:
                raise InstallationError('No files/directories in %s (from %s)' % (base, filename))
            assert filenames, "No files/directories in %s (from %s)" % (base, filename)

            # if we have more than one match, we pick the toplevel one.  This can
            # easily be the case if there is a dist folder which contains an
            # extracted tarball for testing purposes.
            if len(filenames) > 1:
                filenames.sort(key=lambda x: x.count(os.path.sep) +
                                             (os.path.altsep and
                                              x.count(os.path.altsep) or 0))
            self._egg_info_path = os.path.join(base, filenames[0])
        return os.path.join(self._egg_info_path, filename)

def egg_info_lines(self, filename):
        data = self.egg_info_data(filename)
        if not data:
            return []
        result = []
        for line in data.splitlines():
            line = line.strip()
            if not line or line.startswith('#'):
                continue
            result.append(line)
        return result

def from_line(cls, name, comes_from=None, prereleases=None):
        """Creates an InstallRequirement from a name, which might be a
        requirement, directory containing 'setup.py', filename, or URL.
        """
        url = None
        name = name.strip()
        req = None
        path = os.path.normpath(os.path.abspath(name))
        link = None

        if is_url(name):
            link = Link(name)
        elif os.path.isdir(path) and (os.path.sep in name or name.startswith('.')):
            if not is_installable_dir(path):
                raise InstallationError("Directory %r is not installable. File 'setup.py' not found." % name)
            link = Link(path_to_url(name))
        elif is_archive_file(path):
            if not os.path.isfile(path):
                logger.warn('Requirement %r looks like a filename, but the file does not exist', name)
            link = Link(path_to_url(name))

        # If the line has an egg= definition, but isn't editable, pull the requirement out.
        # Otherwise, assume the name is the req for the non URL/path/archive case.
        if link and req is None:
            url = link.url_without_fragment
            req = link.egg_fragment  #when fragment is None, this will become an 'unnamed' requirement

            # Handle relative file URLs
            if link.scheme == 'file' and re.search(r'\.\./', url):
                url = path_to_url(os.path.normpath(os.path.abspath(link.path)))

            # fail early for invalid or unsupported wheels
            if link.ext == wheel_ext:
                wheel = Wheel(link.filename) # can raise InvalidWheelFilename
                if not wheel.supported():
                    raise UnsupportedWheel("%s is not a supported wheel on this platform." % wheel.filename)

        else:
            req = name

        return cls(req, comes_from, url=url, prereleases=prereleases)

def egg_info_data(self, filename):
        if self.satisfied_by is not None:
            if not self.satisfied_by.has_metadata(filename):
                return None
            return self.satisfied_by.get_metadata(filename)
        assert self.source_dir
        filename = self.egg_info_path(filename)
        if not os.path.exists(filename):
            return None
        data = read_text_file(filename)
        return data

def egg_info_path(self, filename):
        if self._egg_info_path is None:
            if self.editable:
                base = self.source_dir
            else:
                base = os.path.join(self.source_dir, 'pip-egg-info')
            filenames = os.listdir(base)
            if self.editable:
                filenames = []
                for root, dirs, files in os.walk(base):
                    for dir in vcs.dirnames:
                        if dir in dirs:
                            dirs.remove(dir)
                    # Iterate over a copy of ``dirs``, since mutating
                    # a list while iterating over it can cause trouble.
                    # (See https://github.com/pypa/pip/pull/462.)
                    for dir in list(dirs):
                        # Don't search in anything that looks like a virtualenv environment
                        if (os.path.exists(os.path.join(root, dir, 'bin', 'python'))
                            or os.path.exists(os.path.join(root, dir, 'Scripts', 'Python.exe'))):
                            dirs.remove(dir)
                        # Also don't search through tests
                        if dir == 'test' or dir == 'tests':
                            dirs.remove(dir)
                    filenames.extend([os.path.join(root, dir)
                                     for dir in dirs])
                filenames = [f for f in filenames if f.endswith('.egg-info')]

            if not filenames:
                raise InstallationError('No files/directories in %s (from %s)' % (base, filename))
            assert filenames, "No files/directories in %s (from %s)" % (base, filename)

            # if we have more than one match, we pick the toplevel one.  This can
            # easily be the case if there is a dist folder which contains an
            # extracted tarball for testing purposes.
            if len(filenames) > 1:
                filenames.sort(key=lambda x: x.count(os.path.sep) +
                                             (os.path.altsep and
                                              x.count(os.path.altsep) or 0))
            self._egg_info_path = os.path.join(base, filenames[0])
        return os.path.join(self._egg_info_path, filename)

def egg_info_lines(self, filename):
        data = self.egg_info_data(filename)
        if not data:
            return []
        result = []
        for line in data.splitlines():
            line = line.strip()
            if not line or line.startswith('#'):
                continue
            result.append(line)
        return result

def egg_info_data(self, filename):
        if self.satisfied_by is not None:
            if not self.satisfied_by.has_metadata(filename):
                return None
            return self.satisfied_by.get_metadata(filename)
        assert self.source_dir
        filename = self.egg_info_path(filename)
        if not os.path.exists(filename):
            return None
        data = read_text_file(filename)
        return data

def from_line(cls, name, comes_from=None, prereleases=None):
        """Creates an InstallRequirement from a name, which might be a
        requirement, directory containing 'setup.py', filename, or URL.
        """
        url = None
        name = name.strip()
        req = None
        path = os.path.normpath(os.path.abspath(name))
        link = None

        if is_url(name):
            link = Link(name)
        elif os.path.isdir(path) and (os.path.sep in name or name.startswith('.')):
            if not is_installable_dir(path):
                raise InstallationError("Directory %r is not installable. File 'setup.py' not found." % name)
            link = Link(path_to_url(name))
        elif is_archive_file(path):
            if not os.path.isfile(path):
                logger.warn('Requirement %r looks like a filename, but the file does not exist', name)
            link = Link(path_to_url(name))

        # If the line has an egg= definition, but isn't editable, pull the requirement out.
        # Otherwise, assume the name is the req for the non URL/path/archive case.
        if link and req is None:
            url = link.url_without_fragment
            req = link.egg_fragment  #when fragment is None, this will become an 'unnamed' requirement

            # Handle relative file URLs
            if link.scheme == 'file' and re.search(r'\.\./', url):
                url = path_to_url(os.path.normpath(os.path.abspath(link.path)))

            # fail early for invalid or unsupported wheels
            if link.ext == wheel_ext:
                wheel = Wheel(link.filename) # can raise InvalidWheelFilename
                if not wheel.supported():
                    raise UnsupportedWheel("%s is not a supported wheel on this platform." % wheel.filename)

        else:
            req = name

        return cls(req, comes_from, url=url, prereleases=prereleases)

def egg_info_data(self, filename):
        if self.satisfied_by is not None:
            if not self.satisfied_by.has_metadata(filename):
                return None
            return self.satisfied_by.get_metadata(filename)
        assert self.source_dir
        filename = self.egg_info_path(filename)
        if not os.path.exists(filename):
            return None
        data = read_text_file(filename)
        return data

def egg_info_path(self, filename):
        if self._egg_info_path is None:
            if self.editable:
                base = self.source_dir
            else:
                base = os.path.join(self.source_dir, 'pip-egg-info')
            filenames = os.listdir(base)
            if self.editable:
                filenames = []
                for root, dirs, files in os.walk(base):
                    for dir in vcs.dirnames:
                        if dir in dirs:
                            dirs.remove(dir)
                    # Iterate over a copy of ``dirs``, since mutating
                    # a list while iterating over it can cause trouble.
                    # (See https://github.com/pypa/pip/pull/462.)
                    for dir in list(dirs):
                        # Don't search in anything that looks like a virtualenv environment
                        if (os.path.exists(os.path.join(root, dir, 'bin', 'python'))
                            or os.path.exists(os.path.join(root, dir, 'Scripts', 'Python.exe'))):
                            dirs.remove(dir)
                        # Also don't search through tests
                        if dir == 'test' or dir == 'tests':
                            dirs.remove(dir)
                    filenames.extend([os.path.join(root, dir)
                                     for dir in dirs])
                filenames = [f for f in filenames if f.endswith('.egg-info')]

            if not filenames:
                raise InstallationError('No files/directories in %s (from %s)' % (base, filename))
            assert filenames, "No files/directories in %s (from %s)" % (base, filename)

            # if we have more than one match, we pick the toplevel one.  This can
            # easily be the case if there is a dist folder which contains an
            # extracted tarball for testing purposes.
            if len(filenames) > 1:
                filenames.sort(key=lambda x: x.count(os.path.sep) +
                                             (os.path.altsep and
                                              x.count(os.path.altsep) or 0))
            self._egg_info_path = os.path.join(base, filenames[0])
        return os.path.join(self._egg_info_path, filename)

def egg_info_lines(self, filename):
        data = self.egg_info_data(filename)
        if not data:
            return []
        result = []
        for line in data.splitlines():
            line = line.strip()
            if not line or line.startswith('#'):
                continue
            result.append(line)
        return result

def from_line(cls, name, comes_from=None, prereleases=None):
        """Creates an InstallRequirement from a name, which might be a
        requirement, directory containing 'setup.py', filename, or URL.
        """
        url = None
        name = name.strip()
        req = None
        path = os.path.normpath(os.path.abspath(name))
        link = None

        if is_url(name):
            link = Link(name)
        elif os.path.isdir(path) and (os.path.sep in name or name.startswith('.')):
            if not is_installable_dir(path):
                raise InstallationError("Directory %r is not installable. File 'setup.py' not found." % name)
            link = Link(path_to_url(name))
        elif is_archive_file(path):
            if not os.path.isfile(path):
                logger.warn('Requirement %r looks like a filename, but the file does not exist', name)
            link = Link(path_to_url(name))

        # If the line has an egg= definition, but isn't editable, pull the requirement out.
        # Otherwise, assume the name is the req for the non URL/path/archive case.
        if link and req is None:
            url = link.url_without_fragment
            req = link.egg_fragment  #when fragment is None, this will become an 'unnamed' requirement

            # Handle relative file URLs
            if link.scheme == 'file' and re.search(r'\.\./', url):
                url = path_to_url(os.path.normpath(os.path.abspath(link.path)))

            # fail early for invalid or unsupported wheels
            if link.ext == wheel_ext:
                wheel = Wheel(link.filename) # can raise InvalidWheelFilename
                if not wheel.supported():
                    raise UnsupportedWheel("%s is not a supported wheel on this platform." % wheel.filename)

        else:
            req = name

        return cls(req, comes_from, url=url, prereleases=prereleases)

def egg_info_data(self, filename):
        if self.satisfied_by is not None:
            if not self.satisfied_by.has_metadata(filename):
                return None
            return self.satisfied_by.get_metadata(filename)
        assert self.source_dir
        filename = self.egg_info_path(filename)
        if not os.path.exists(filename):
            return None
        data = read_text_file(filename)
        return data

def egg_info_path(self, filename):
        if self._egg_info_path is None:
            if self.editable:
                base = self.source_dir
            else:
                base = os.path.join(self.source_dir, 'pip-egg-info')
            filenames = os.listdir(base)
            if self.editable:
                filenames = []
                for root, dirs, files in os.walk(base):
                    for dir in vcs.dirnames:
                        if dir in dirs:
                            dirs.remove(dir)
                    # Iterate over a copy of ``dirs``, since mutating
                    # a list while iterating over it can cause trouble.
                    # (See https://github.com/pypa/pip/pull/462.)
                    for dir in list(dirs):
                        # Don't search in anything that looks like a virtualenv environment
                        if (os.path.exists(os.path.join(root, dir, 'bin', 'python'))
                            or os.path.exists(os.path.join(root, dir, 'Scripts', 'Python.exe'))):
                            dirs.remove(dir)
                        # Also don't search through tests
                        if dir == 'test' or dir == 'tests':
                            dirs.remove(dir)
                    filenames.extend([os.path.join(root, dir)
                                     for dir in dirs])
                filenames = [f for f in filenames if f.endswith('.egg-info')]

            if not filenames:
                raise InstallationError('No files/directories in %s (from %s)' % (base, filename))
            assert filenames, "No files/directories in %s (from %s)" % (base, filename)

            # if we have more than one match, we pick the toplevel one.  This can
            # easily be the case if there is a dist folder which contains an
            # extracted tarball for testing purposes.
            if len(filenames) > 1:
                filenames.sort(key=lambda x: x.count(os.path.sep) +
                                             (os.path.altsep and
                                              x.count(os.path.altsep) or 0))
            self._egg_info_path = os.path.join(base, filenames[0])
        return os.path.join(self._egg_info_path, filename)

def egg_info_lines(self, filename):
        data = self.egg_info_data(filename)
        if not data:
            return []
        result = []
        for line in data.splitlines():
            line = line.strip()
            if not line or line.startswith('#'):
                continue
            result.append(line)
        return result

def from_line(cls, name, comes_from=None, prereleases=None):
        """Creates an InstallRequirement from a name, which might be a
        requirement, directory containing 'setup.py', filename, or URL.
        """
        url = None
        name = name.strip()
        req = None
        path = os.path.normpath(os.path.abspath(name))
        link = None

        if is_url(name):
            link = Link(name)
        elif os.path.isdir(path) and (os.path.sep in name or name.startswith('.')):
            if not is_installable_dir(path):
                raise InstallationError("Directory %r is not installable. File 'setup.py' not found." % name)
            link = Link(path_to_url(name))
        elif is_archive_file(path):
            if not os.path.isfile(path):
                logger.warn('Requirement %r looks like a filename, but the file does not exist', name)
            link = Link(path_to_url(name))

        # If the line has an egg= definition, but isn't editable, pull the requirement out.
        # Otherwise, assume the name is the req for the non URL/path/archive case.
        if link and req is None:
            url = link.url_without_fragment
            req = link.egg_fragment  #when fragment is None, this will become an 'unnamed' requirement

            # Handle relative file URLs
            if link.scheme == 'file' and re.search(r'\.\./', url):
                url = path_to_url(os.path.normpath(os.path.abspath(link.path)))

            # fail early for invalid or unsupported wheels
            if link.ext == wheel_ext:
                wheel = Wheel(link.filename) # can raise InvalidWheelFilename
                if not wheel.supported():
                    raise UnsupportedWheel("%s is not a supported wheel on this platform." % wheel.filename)

        else:
            req = name

        return cls(req, comes_from, url=url, prereleases=prereleases)