import re

# Valid query types (a dictionary is used for speedy lookups).

QUERY_TERMS = dict([(x, None) for x in (

    'exact', 'iexact', 'contains', 'icontains', 'gt', 'gte', 'lt', 'lte', 'in',

    'startswith', 'istartswith', 'endswith', 'iendswith', 'range', 'year',

    'month', 'day', 'week_day', 'isnull', 'search', 'regex', 'iregex',

    )])

# Size of each "chunk" for get_iterator calls.

# Larger values are slightly faster at the expense of more storage space.

GET_ITERATOR_CHUNK_SIZE = 100

# Separator used to split filter strings apart.

LOOKUP_SEP = '__'

# Constants to make looking up tuple values clearer.

# Join lists (indexes into the tuples that are values in the alias_map

# dictionary in the Query class).

TABLE_NAME = 0

RHS_ALIAS = 1

JOIN_TYPE = 2

LHS_ALIAS = 3

LHS_JOIN_COL = 4

RHS_JOIN_COL = 5

NULLABLE = 6

# How many results to expect from a cursor.execute call

MULTI = 'multi'

SINGLE = 'single'

ORDER_PATTERN = re.compile(r'\?|[-+]?[.\w]+$')

ORDER_DIR = {

    'ASC': ('ASC', 'DESC'),

    'DESC': ('DESC', 'ASC')}