How to use the sqlparse.tokens.String function in sqlparse

def test_comparison_with_strings():
    # issue148
    p = sqlparse.parse("foo = 'bar'")[0]
    assert len(p.tokens) == 1
    assert isinstance(p.tokens[0], sql.Comparison)
    assert p.tokens[0].right.value == "'bar'"
    assert p.tokens[0].right.ttype == T.String.Single

def test_issue212_py2unicode():
    t1 = sql.Token(T.String, u'schöner ')
    t2 = sql.Token(T.String, 'bug')
    token_list = sql.TokenList([t1, t2])
    assert str(token_list) == 'schöner bug'

                   lambda t: t.ttype == T.String.Single,
                   lambda t: isinstance(t, sql.Comparison),

"""A list of :class:`~sqlparse.sql.Identifier`\'s."""

    def get_identifiers(self):
        """Returns the identifiers.

        Whitespaces and punctuations are not included in this generator.
        """
        for token in self.tokens:
            if not (token.is_whitespace or token.match(T.Punctuation, ',')):
                yield token


class TypedLiteral(TokenList):
    """A typed literal, such as "date '2001-09-28'" or "interval '2 hours'"."""
    M_OPEN = T.Name.Builtin, None
    M_CLOSE = T.String.Single, None
    M_EXTEND = T.Keyword, ("DAY", "MONTH", "YEAR", "HOUR", "MINUTE", "SECOND")


class Parenthesis(TokenList):
    """Tokens between parenthesis."""
    M_OPEN = T.Punctuation, '('
    M_CLOSE = T.Punctuation, ')'

    @property
    def _groupable_tokens(self):
        return self.tokens[1:-1]


class SquareBrackets(TokenList):
    """Tokens between square brackets"""
    M_OPEN = T.Punctuation, '['

def process(self, stack, stream):
        # Run over all tokens in the stream
        for token_type, value in stream:
            # INCLUDE statement found, set detected mode
            if token_type in Name and value.upper() == 'INCLUDE':
                self.detected = True
                continue

            # INCLUDE statement was found, parse it
            elif self.detected:
                # Omit whitespaces
                if token_type in Whitespace:
                    continue

                # Found file path to include
                if token_type in String.Symbol:
#                if token_type in tokens.String.Symbol:

                    # Get path of file to include
                    path = join(self.dirpath, value[1:-1])

                    try:
                        f = open(path)
                        raw_sql = f.read()
                        f.close()

                    # There was a problem loading the include file
                    except IOError as err:
                        # Raise the exception to the interpreter
                        if self.raiseexceptions:
                            raise

# -*- coding: utf-8 -*-
#
# Copyright (C) 2009-2018 the sqlparse authors and contributors
# 
#
# This module is part of python-sqlparse and is released under
# the BSD License: https://opensource.org/licenses/BSD-3-Clause

from sqlparse import sql
from sqlparse import tokens as T
from sqlparse.utils import recurse, imt

T_NUMERICAL = (T.Number, T.Number.Integer, T.Number.Float)
T_STRING = (T.String, T.String.Single, T.String.Symbol)
T_NAME = (T.Name, T.Name.Placeholder)


def _group_matching(tlist, cls):
    """Groups Tokens that have beginning and end."""
    opens = []
    tidx_offset = 0
    for idx, token in enumerate(list(tlist)):
        tidx = idx - tidx_offset

        if token.is_whitespace:
            # ~50% of tokens will be whitespace. Will checking early
            # for them avoid 3 comparisons, but then add 1 more comparison
            # for the other ~50% of tokens...
            continue

                   lambda t: t.ttype == T.String.Single,
                   lambda t: t.ttype == T.Name.Placeholder,

# see issue #39
        # Spaces around period `schema . name` are valid identifier
        # TODO: Spaces before period not implemented
        (r'[A-ZÀ-Ü]\w*(?=\s*\.)', tokens.Name),  # 'Name'   .
        # FIXME(atronah): never match,
        # because `re.match` doesn't work with look-behind regexp feature
        (r'(?<=\.)[A-ZÀ-Ü]\w*', tokens.Name),  # .'Name'
        (r'[A-ZÀ-Ü]\w*(?=\()', tokens.Name),  # side effect: change kw to func
        (r'-?0x[\dA-F]+', tokens.Number.Hexadecimal),
        (r'-?\d*(\.\d+)?E-?\d+', tokens.Number.Float),
        (r'(?![_A-ZÀ-Ü])-?(\d+(\.\d*)|\.\d+)(?![_A-ZÀ-Ü])',
         tokens.Number.Float),
        (r'(?![_A-ZÀ-Ü])-?\d+(?![_A-ZÀ-Ü])', tokens.Number.Integer),
        (r"'(''|\\\\|\\'|[^'])*'", tokens.String.Single),
        # not a real string literal in ANSI SQL:
        (r'"(""|\\\\|\\"|[^"])*"', tokens.String.Symbol),
        (r'(""|".*?[^\\]")', tokens.String.Symbol),
        # sqlite names can be escaped with [square brackets]. left bracket
        # cannot be preceded by word character or a right bracket --
        # otherwise it's probably an array index
        (r'(?

for token_type, value in stream:
            # INCLUDE statement found, set detected mode
            if token_type in Name and value.upper() == 'INCLUDE':
                self.detected = True
                continue

            # INCLUDE statement was found, parse it
            elif self.detected:
                # Omit whitespaces
                if token_type in Whitespace:
                    pass

                # Get path of file to include
                path = None

                if token_type in String.Symbol:
#                if token_type in tokens.String.Symbol:
                    path = join(self.dirpath, value[1:-1])

                # Include file if path was found
                if path:
                    try:
                        f = open(path)
                        raw_sql = f.read()
                        f.close()
                    except IOError as err:
                        yield Comment, u'-- IOError: %s\n' % err

                    else:
                        # Create new FilterStack to parse readed file
                        # and add all its tokens to the main stack recursively
                        # [ToDo] Add maximum recursive iteration value

"""

        # Strip the alias if present.
        idx = len(tlist.tokens)

        if tlist.has_alias():
            ws_idx, _ = tlist.token_next_by(t=Whitespace)

            if ws_idx != -1:
                idx = ws_idx

        tokens = tlist.tokens[:idx]

        if (
            len(tokens) in (1, 3, 5)
            and all(imt(token, t=[Name, String]) for token in tokens[0::2])
            and all(imt(token, m=(Punctuation, ".")) for token in tokens[1::2])
        ):
            return ".".join([remove_quotes(token.value) for token in tokens[0::2]])

        return None