Python django.utils.six.moves.zip() Examples

def from_db(cls, db, field_names, values):
        if cls._deferred:
            new = cls(**dict(zip(field_names, values)))
        else:
            new = cls(*values)
        new._state.adding = False
        new._state.db = db
        return new 

def assemble_as_sql(self, fields, value_rows):
        """
        Take a sequence of N fields and a sequence of M rows of values,
        generate placeholder SQL and parameters for each field and value, and
        return a pair containing:
         * a sequence of M rows of N SQL placeholder strings, and
         * a sequence of M rows of corresponding parameter values.

        Each placeholder string may contain any number of '%s' interpolation
        strings, and each parameter row will contain exactly as many params
        as the total number of '%s's in the corresponding placeholder row.
        """
        if not value_rows:
            return [], []

        # list of (sql, [params]) tuples for each object to be saved
        # Shape: [n_objs][n_fields][2]
        rows_of_fields_as_sql = (
            (self.field_as_sql(field, v) for field, v in zip(fields, row))
            for row in value_rows
        )

        # tuple like ([sqls], [[params]s]) for each object to be saved
        # Shape: [n_objs][2][n_fields]
        sql_and_param_pair_rows = (zip(*row) for row in rows_of_fields_as_sql)

        # Extract separate lists for placeholders and params.
        # Each of these has shape [n_objs][n_fields]
        placeholder_rows, param_rows = zip(*sql_and_param_pair_rows)

        # Params for each field are still lists, and need to be flattened.
        param_rows = [[p for ps in row for p in ps] for row in param_rows]

        return placeholder_rows, param_rows 

def get_combinator_sql(self, combinator, all):
        features = self.connection.features
        compilers = [
            query.get_compiler(self.using, self.connection)
            for query in self.query.combined_queries if not query.is_empty()
        ]
        if not features.supports_slicing_ordering_in_compound:
            for query, compiler in zip(self.query.combined_queries, compilers):
                if query.low_mark or query.high_mark:
                    raise DatabaseError('LIMIT/OFFSET not allowed in subqueries of compound statements.')
                if compiler.get_order_by():
                    raise DatabaseError('ORDER BY not allowed in subqueries of compound statements.')
        parts = ()
        for compiler in compilers:
            try:
                parts += (compiler.as_sql(),)
            except EmptyResultSet:
                # Omit the empty queryset with UNION and with DIFFERENCE if the
                # first queryset is nonempty.
                if combinator == 'union' or (combinator == 'difference' and parts):
                    continue
                raise
        if not parts:
            raise EmptyResultSet
        combinator_sql = self.connection.ops.set_operators[combinator]
        if all and combinator == 'union':
            combinator_sql += ' ALL'
        braces = '({})' if features.supports_slicing_ordering_in_compound else '{}'
        sql_parts, args_parts = zip(*((braces.format(sql), args) for sql, args in parts))
        result = [' {} '.format(combinator_sql).join(sql_parts)]
        params = []
        for part in args_parts:
            params.extend(part)
        return result, params 

def _unsalt_cipher_token(token):
    """
    Given a token (assumed to be a string of CSRF_ALLOWED_CHARS, of length
    CSRF_TOKEN_LENGTH, and that its first half is a salt), use it to decrypt
    the second half to produce the original secret.
    """
    salt = token[:CSRF_SECRET_LENGTH]
    token = token[CSRF_SECRET_LENGTH:]
    chars = CSRF_ALLOWED_CHARS
    pairs = zip((chars.index(x) for x in token), (chars.index(x) for x in salt))
    secret = ''.join(chars[x - y] for x, y in pairs)  # Note negative values are ok
    return secret 

def _salt_cipher_secret(secret):
    """
    Given a secret (assumed to be a string of CSRF_ALLOWED_CHARS), generate a
    token by adding a salt and using it to encrypt the secret.
    """
    salt = _get_new_csrf_string()
    chars = CSRF_ALLOWED_CHARS
    pairs = zip((chars.index(x) for x in secret), (chars.index(x) for x in salt))
    cipher = ''.join(chars[(x + y) % len(chars)] for x, y in pairs)
    return salt + cipher 

def assemble_as_sql(self, fields, value_rows):
        """
        Take a sequence of N fields and a sequence of M rows of values,
        generate placeholder SQL and parameters for each field and value, and
        return a pair containing:
         * a sequence of M rows of N SQL placeholder strings, and
         * a sequence of M rows of corresponding parameter values.

        Each placeholder string may contain any number of '%s' interpolation
        strings, and each parameter row will contain exactly as many params
        as the total number of '%s's in the corresponding placeholder row.
        """
        if not value_rows:
            return [], []

        # list of (sql, [params]) tuples for each object to be saved
        # Shape: [n_objs][n_fields][2]
        rows_of_fields_as_sql = (
            (self.field_as_sql(field, v) for field, v in zip(fields, row))
            for row in value_rows
        )

        # tuple like ([sqls], [[params]s]) for each object to be saved
        # Shape: [n_objs][2][n_fields]
        sql_and_param_pair_rows = (zip(*row) for row in rows_of_fields_as_sql)

        # Extract separate lists for placeholders and params.
        # Each of these has shape [n_objs][n_fields]
        placeholder_rows, param_rows = zip(*sql_and_param_pair_rows)

        # Params for each field are still lists, and need to be flattened.
        param_rows = [[p for ps in row for p in ps] for row in param_rows]

        return placeholder_rows, param_rows 

def from_db(cls, db, field_names, values):
        if cls._deferred:
            new = cls(**dict(zip(field_names, values)))
        else:
            new = cls(*values)
        new._state.adding = False
        new._state.db = db
        return new 

def assemble_as_sql(self, fields, value_rows):
        """
        Take a sequence of N fields and a sequence of M rows of values,
        generate placeholder SQL and parameters for each field and value, and
        return a pair containing:
         * a sequence of M rows of N SQL placeholder strings, and
         * a sequence of M rows of corresponding parameter values.

        Each placeholder string may contain any number of '%s' interpolation
        strings, and each parameter row will contain exactly as many params
        as the total number of '%s's in the corresponding placeholder row.
        """
        if not value_rows:
            return [], []

        # list of (sql, [params]) tuples for each object to be saved
        # Shape: [n_objs][n_fields][2]
        rows_of_fields_as_sql = (
            (self.field_as_sql(field, v) for field, v in zip(fields, row))
            for row in value_rows
        )

        # tuple like ([sqls], [[params]s]) for each object to be saved
        # Shape: [n_objs][2][n_fields]
        sql_and_param_pair_rows = (zip(*row) for row in rows_of_fields_as_sql)

        # Extract separate lists for placeholders and params.
        # Each of these has shape [n_objs][n_fields]
        placeholder_rows, param_rows = zip(*sql_and_param_pair_rows)

        # Params for each field are still lists, and need to be flattened.
        param_rows = [[p for ps in row for p in ps] for row in param_rows]

        return placeholder_rows, param_rows 

def get_combinator_sql(self, combinator, all):
        features = self.connection.features
        compilers = [
            query.get_compiler(self.using, self.connection)
            for query in self.query.combined_queries if not query.is_empty()
        ]
        if not features.supports_slicing_ordering_in_compound:
            for query, compiler in zip(self.query.combined_queries, compilers):
                if query.low_mark or query.high_mark:
                    raise DatabaseError('LIMIT/OFFSET not allowed in subqueries of compound statements.')
                if compiler.get_order_by():
                    raise DatabaseError('ORDER BY not allowed in subqueries of compound statements.')
        parts = ()
        for compiler in compilers:
            try:
                parts += (compiler.as_sql(),)
            except EmptyResultSet:
                # Omit the empty queryset with UNION and with DIFFERENCE if the
                # first queryset is nonempty.
                if combinator == 'union' or (combinator == 'difference' and parts):
                    continue
                raise
        if not parts:
            raise EmptyResultSet
        combinator_sql = self.connection.ops.set_operators[combinator]
        if all and combinator == 'union':
            combinator_sql += ' ALL'
        braces = '({})' if features.supports_slicing_ordering_in_compound else '{}'
        sql_parts, args_parts = zip(*((braces.format(sql), args) for sql, args in parts))
        result = [' {} '.format(combinator_sql).join(sql_parts)]
        params = []
        for part in args_parts:
            params.extend(part)
        return result, params 

def _unsalt_cipher_token(token):
    """
    Given a token (assumed to be a string of CSRF_ALLOWED_CHARS, of length
    CSRF_TOKEN_LENGTH, and that its first half is a salt), use it to decrypt
    the second half to produce the original secret.
    """
    salt = token[:CSRF_SECRET_LENGTH]
    token = token[CSRF_SECRET_LENGTH:]
    chars = CSRF_ALLOWED_CHARS
    pairs = zip((chars.index(x) for x in token), (chars.index(x) for x in salt))
    secret = ''.join(chars[x - y] for x, y in pairs)  # Note negative values are ok
    return secret 

def _salt_cipher_secret(secret):
    """
    Given a secret (assumed to be a string of CSRF_ALLOWED_CHARS), generate a
    token by adding a salt and using it to encrypt the secret.
    """
    salt = _get_new_csrf_string()
    chars = CSRF_ALLOWED_CHARS
    pairs = zip((chars.index(x) for x in secret), (chars.index(x) for x in salt))
    cipher = ''.join(chars[(x + y) % len(chars)] for x, y in pairs)
    return salt + cipher 

def flatten_result(source):
    """
    Turns the given source sequence into a list of reg-exp possibilities and
    their arguments. Returns a list of strings and a list of argument lists.
    Each of the two lists will be of the same length.
    """
    if source is None:
        return [''], [[]]
    if isinstance(source, Group):
        if source[1] is None:
            params = []
        else:
            params = [source[1]]
        return [source[0]], [params]
    result = ['']
    result_args = [[]]
    pos = last = 0
    for pos, elt in enumerate(source):
        if isinstance(elt, six.string_types):
            continue
        piece = ''.join(source[last:pos])
        if isinstance(elt, Group):
            piece += elt[0]
            param = elt[1]
        else:
            param = None
        last = pos + 1
        for i in range(len(result)):
            result[i] += piece
            if param:
                result_args[i].append(param)
        if isinstance(elt, (Choice, NonCapture)):
            if isinstance(elt, NonCapture):
                elt = [elt]
            inner_result, inner_args = [], []
            for item in elt:
                res, args = flatten_result(item)
                inner_result.extend(res)
                inner_args.extend(args)
            new_result = []
            new_args = []
            for item, args in zip(result, result_args):
                for i_item, i_args in zip(inner_result, inner_args):
                    new_result.append(item + i_item)
                    new_args.append(args[:] + i_args)
            result = new_result
            result_args = new_args
    if pos >= last:
        piece = ''.join(source[last:])
        for i in range(len(result)):
            result[i] += piece
    return result, result_args 

def results_iter(self):
        """
        Returns an iterator over the results from executing this query.
        """
        resolve_columns = hasattr(self, 'resolve_columns')
        fields = None
        has_aggregate_select = bool(self.query.aggregate_select)
        # Set transaction dirty if we're using SELECT FOR UPDATE to ensure
        # a subsequent commit/rollback is executed, so any database locks
        # are released.
        if self.query.select_for_update and transaction.is_managed(self.using):
            transaction.set_dirty(self.using)
        for rows in self.execute_sql(MULTI):
            for row in rows:
                if resolve_columns:
                    if fields is None:
                        # We only set this up here because
                        # related_select_fields isn't populated until
                        # execute_sql() has been called.

                        # We also include types of fields of related models that
                        # will be included via select_related() for the benefit
                        # of MySQL/MySQLdb when boolean fields are involved
                        # (#15040).

                        # This code duplicates the logic for the order of fields
                        # found in get_columns(). It would be nice to clean this up.
                        if self.query.select_fields:
                            fields = self.query.select_fields
                        else:
                            fields = self.query.model._meta.fields
                        fields = fields + self.query.related_select_fields

                        # If the field was deferred, exclude it from being passed
                        # into `resolve_columns` because it wasn't selected.
                        only_load = self.deferred_to_columns()
                        if only_load:
                            db_table = self.query.model._meta.db_table
                            fields = [f for f in fields if db_table in only_load and
                                      f.column in only_load[db_table]]
                    row = self.resolve_columns(row, fields)

                if has_aggregate_select:
                    aggregate_start = len(self.query.extra_select) + len(self.query.select)
                    aggregate_end = aggregate_start + len(self.query.aggregate_select)
                    row = tuple(row[:aggregate_start]) + tuple([
                        self.query.resolve_aggregate(value, aggregate, self.connection)
                        for (alias, aggregate), value
                        in zip(self.query.aggregate_select.items(), row[aggregate_start:aggregate_end])
                    ]) + tuple(row[aggregate_end:])

                yield row 

def as_sql(self):
        # We don't need quote_name_unless_alias() here, since these are all
        # going to be column names (so we can avoid the extra overhead).
        qn = self.connection.ops.quote_name
        opts = self.query.model._meta
        result = ['INSERT INTO %s' % qn(opts.db_table)]

        has_fields = bool(self.query.fields)
        fields = self.query.fields if has_fields else [opts.pk]
        result.append('(%s)' % ', '.join([qn(f.column) for f in fields]))

        if has_fields:
            params = values = [
                [
                    f.get_db_prep_save(getattr(obj, f.attname) if self.query.raw else f.pre_save(obj, True), connection=self.connection)
                    for f in fields
                ]
                for obj in self.query.objs
            ]
        else:
            values = [[self.connection.ops.pk_default_value()] for obj in self.query.objs]
            params = [[]]
            fields = [None]
        can_bulk = (not any(hasattr(field, "get_placeholder") for field in fields) and
            not self.return_id and self.connection.features.has_bulk_insert)

        if can_bulk:
            placeholders = [["%s"] * len(fields)]
        else:
            placeholders = [
                [self.placeholder(field, v) for field, v in zip(fields, val)]
                for val in values
            ]
            # Oracle Spatial needs to remove some values due to #10888
            params = self.connection.ops.modify_insert_params(placeholders, params)
        if self.return_id and self.connection.features.can_return_id_from_insert:
            params = params[0]
            col = "%s.%s" % (qn(opts.db_table), qn(opts.pk.column))
            result.append("VALUES (%s)" % ", ".join(placeholders[0]))
            r_fmt, r_params = self.connection.ops.return_insert_id()
            # Skip empty r_fmt to allow subclasses to customize behaviour for
            # 3rd party backends. Refs #19096.
            if r_fmt:
                result.append(r_fmt % col)
                params += r_params
            return [(" ".join(result), tuple(params))]
        if can_bulk:
            result.append(self.connection.ops.bulk_insert_sql(fields, len(values)))
            return [(" ".join(result), tuple([v for val in values for v in val]))]
        else:
            return [
                (" ".join(result + ["VALUES (%s)" % ", ".join(p)]), vals)
                for p, vals in zip(placeholders, params)
            ] 

def flatten_result(source):
    """
    Turns the given source sequence into a list of reg-exp possibilities and
    their arguments. Returns a list of strings and a list of argument lists.
    Each of the two lists will be of the same length.
    """
    if source is None:
        return [''], [[]]
    if isinstance(source, Group):
        if source[1] is None:
            params = []
        else:
            params = [source[1]]
        return [source[0]], [params]
    result = ['']
    result_args = [[]]
    pos = last = 0
    for pos, elt in enumerate(source):
        if isinstance(elt, six.string_types):
            continue
        piece = ''.join(source[last:pos])
        if isinstance(elt, Group):
            piece += elt[0]
            param = elt[1]
        else:
            param = None
        last = pos + 1
        for i in range(len(result)):
            result[i] += piece
            if param:
                result_args[i].append(param)
        if isinstance(elt, (Choice, NonCapture)):
            if isinstance(elt, NonCapture):
                elt = [elt]
            inner_result, inner_args = [], []
            for item in elt:
                res, args = flatten_result(item)
                inner_result.extend(res)
                inner_args.extend(args)
            new_result = []
            new_args = []
            for item, args in zip(result, result_args):
                for i_item, i_args in zip(inner_result, inner_args):
                    new_result.append(item + i_item)
                    new_args.append(args[:] + i_args)
            result = new_result
            result_args = new_args
    if pos >= last:
        piece = ''.join(source[last:])
        for i in range(len(result)):
            result[i] += piece
    return result, result_args 

def flatten_result(source):
    """
    Turns the given source sequence into a list of reg-exp possibilities and
    their arguments. Returns a list of strings and a list of argument lists.
    Each of the two lists will be of the same length.
    """
    if source is None:
        return [''], [[]]
    if isinstance(source, Group):
        if source[1] is None:
            params = []
        else:
            params = [source[1]]
        return [source[0]], [params]
    result = ['']
    result_args = [[]]
    pos = last = 0
    for pos, elt in enumerate(source):
        if isinstance(elt, six.string_types):
            continue
        piece = ''.join(source[last:pos])
        if isinstance(elt, Group):
            piece += elt[0]
            param = elt[1]
        else:
            param = None
        last = pos + 1
        for i in range(len(result)):
            result[i] += piece
            if param:
                result_args[i].append(param)
        if isinstance(elt, (Choice, NonCapture)):
            if isinstance(elt, NonCapture):
                elt = [elt]
            inner_result, inner_args = [], []
            for item in elt:
                res, args = flatten_result(item)
                inner_result.extend(res)
                inner_args.extend(args)
            new_result = []
            new_args = []
            for item, args in zip(result, result_args):
                for i_item, i_args in zip(inner_result, inner_args):
                    new_result.append(item + i_item)
                    new_args.append(args[:] + i_args)
            result = new_result
            result_args = new_args
    if pos >= last:
        piece = ''.join(source[last:])
        for i in range(len(result)):
            result[i] += piece
    return result, result_args 

def as_sql(self):
        # We don't need quote_name_unless_alias() here, since these are all
        # going to be column names (so we can avoid the extra overhead).
        qn = self.connection.ops.quote_name
        opts = self.query.get_meta()
        result = ['INSERT INTO %s' % qn(opts.db_table)]

        has_fields = bool(self.query.fields)
        fields = self.query.fields if has_fields else [opts.pk]
        result.append('(%s)' % ', '.join(qn(f.column) for f in fields))

        if has_fields:
            value_rows = [
                [self.prepare_value(field, self.pre_save_val(field, obj)) for field in fields]
                for obj in self.query.objs
            ]
        else:
            # An empty object.
            value_rows = [[self.connection.ops.pk_default_value()] for _ in self.query.objs]
            fields = [None]

        # Currently the backends just accept values when generating bulk
        # queries and generate their own placeholders. Doing that isn't
        # necessary and it should be possible to use placeholders and
        # expressions in bulk inserts too.
        can_bulk = (not self.return_id and self.connection.features.has_bulk_insert)

        placeholder_rows, param_rows = self.assemble_as_sql(fields, value_rows)

        if self.return_id and self.connection.features.can_return_id_from_insert:
            params = param_rows[0]
            col = "%s.%s" % (qn(opts.db_table), qn(opts.pk.column))
            result.append("VALUES (%s)" % ", ".join(placeholder_rows[0]))
            r_fmt, r_params = self.connection.ops.return_insert_id()
            # Skip empty r_fmt to allow subclasses to customize behavior for
            # 3rd party backends. Refs #19096.
            if r_fmt:
                result.append(r_fmt % col)
                params += r_params
            return [(" ".join(result), tuple(params))]

        if can_bulk:
            result.append(self.connection.ops.bulk_insert_sql(fields, placeholder_rows))
            return [(" ".join(result), tuple(p for ps in param_rows for p in ps))]
        else:
            return [
                (" ".join(result + ["VALUES (%s)" % ", ".join(p)]), vals)
                for p, vals in zip(placeholder_rows, param_rows)
            ] 

def flatten_result(source):
    """
    Turns the given source sequence into a list of reg-exp possibilities and
    their arguments. Returns a list of strings and a list of argument lists.
    Each of the two lists will be of the same length.
    """
    if source is None:
        return [''], [[]]
    if isinstance(source, Group):
        if source[1] is None:
            params = []
        else:
            params = [source[1]]
        return [source[0]], [params]
    result = ['']
    result_args = [[]]
    pos = last = 0
    for pos, elt in enumerate(source):
        if isinstance(elt, six.string_types):
            continue
        piece = ''.join(source[last:pos])
        if isinstance(elt, Group):
            piece += elt[0]
            param = elt[1]
        else:
            param = None
        last = pos + 1
        for i in range(len(result)):
            result[i] += piece
            if param:
                result_args[i].append(param)
        if isinstance(elt, (Choice, NonCapture)):
            if isinstance(elt, NonCapture):
                elt = [elt]
            inner_result, inner_args = [], []
            for item in elt:
                res, args = flatten_result(item)
                inner_result.extend(res)
                inner_args.extend(args)
            new_result = []
            new_args = []
            for item, args in zip(result, result_args):
                for i_item, i_args in zip(inner_result, inner_args):
                    new_result.append(item + i_item)
                    new_args.append(args[:] + i_args)
            result = new_result
            result_args = new_args
    if pos >= last:
        piece = ''.join(source[last:])
        for i in range(len(result)):
            result[i] += piece
    return result, result_args 

def as_sql(self):
        # We don't need quote_name_unless_alias() here, since these are all
        # going to be column names (so we can avoid the extra overhead).
        qn = self.connection.ops.quote_name
        opts = self.query.get_meta()
        result = ['INSERT INTO %s' % qn(opts.db_table)]

        has_fields = bool(self.query.fields)
        fields = self.query.fields if has_fields else [opts.pk]
        result.append('(%s)' % ', '.join(qn(f.column) for f in fields))

        if has_fields:
            params = values = [
                [
                    f.get_db_prep_save(
                        getattr(obj, f.attname) if self.query.raw else f.pre_save(obj, True),
                        connection=self.connection
                    ) for f in fields
                ]
                for obj in self.query.objs
            ]
        else:
            values = [[self.connection.ops.pk_default_value()] for obj in self.query.objs]
            params = [[]]
            fields = [None]
        can_bulk = (not any(hasattr(field, "get_placeholder") for field in fields) and
            not self.return_id and self.connection.features.has_bulk_insert)

        if can_bulk:
            placeholders = [["%s"] * len(fields)]
        else:
            placeholders = [
                [self.placeholder(field, v) for field, v in zip(fields, val)]
                for val in values
            ]
            # Oracle Spatial needs to remove some values due to #10888
            params = self.connection.ops.modify_insert_params(placeholders, params)
        if self.return_id and self.connection.features.can_return_id_from_insert:
            params = params[0]
            col = "%s.%s" % (qn(opts.db_table), qn(opts.pk.column))
            result.append("VALUES (%s)" % ", ".join(placeholders[0]))
            r_fmt, r_params = self.connection.ops.return_insert_id()
            # Skip empty r_fmt to allow subclasses to customize behavior for
            # 3rd party backends. Refs #19096.
            if r_fmt:
                result.append(r_fmt % col)
                params += r_params
            return [(" ".join(result), tuple(params))]
        if can_bulk:
            result.append(self.connection.ops.bulk_insert_sql(fields, len(values)))
            return [(" ".join(result), tuple(v for val in values for v in val))]
        else:
            return [
                (" ".join(result + ["VALUES (%s)" % ", ".join(p)]), vals)
                for p, vals in zip(placeholders, params)
            ] 

def flatten_result(source):
    """
    Turns the given source sequence into a list of reg-exp possibilities and
    their arguments. Returns a list of strings and a list of argument lists.
    Each of the two lists will be of the same length.
    """
    if source is None:
        return [''], [[]]
    if isinstance(source, Group):
        if source[1] is None:
            params = []
        else:
            params = [source[1]]
        return [source[0]], [params]
    result = ['']
    result_args = [[]]
    pos = last = 0
    for pos, elt in enumerate(source):
        if isinstance(elt, six.string_types):
            continue
        piece = ''.join(source[last:pos])
        if isinstance(elt, Group):
            piece += elt[0]
            param = elt[1]
        else:
            param = None
        last = pos + 1
        for i in range(len(result)):
            result[i] += piece
            if param:
                result_args[i].append(param)
        if isinstance(elt, (Choice, NonCapture)):
            if isinstance(elt, NonCapture):
                elt = [elt]
            inner_result, inner_args = [], []
            for item in elt:
                res, args = flatten_result(item)
                inner_result.extend(res)
                inner_args.extend(args)
            new_result = []
            new_args = []
            for item, args in zip(result, result_args):
                for i_item, i_args in zip(inner_result, inner_args):
                    new_result.append(item + i_item)
                    new_args.append(args[:] + i_args)
            result = new_result
            result_args = new_args
    if pos >= last:
        piece = ''.join(source[last:])
        for i in range(len(result)):
            result[i] += piece
    return result, result_args