students = [dict(firstname='Joe', lastname='Blogs', scores=[56, 23, 21, 89]),
dict(firstname='John', lastname='Doe', scores=[34, 12, 92, 93]),
dict(firstname='Jane', lastname='Doe', scores=[33, 94, 91, 13]),
dict(firstname='Ola', lastname='Nordmann', scores=[98, 23, 98, 87]),
dict(firstname='Kari', lastname='Nordmann', scores=[86, 37, 88, 87]),
dict(firstname='Mario', lastname='Rossi', scores=[37, 95, 45, 18])]
# Find all students where the first score is over 90
first_over_90 = query(students).where(lambda student: student['scores'][0] > 90)
# Select the last name of students where the first score is over 90
query(students).where(lambda student: student['scores'][0] > 90) \
.select(lambda student: student['lastname'])
# Compute the maximum of all scores overall
query(students).select_many(lambda student: student['scores']).max()
# Order the students by last name and then by first name
query(students).order_by(lambda x: x['lastname']) \
.then_by(lambda x: x['firstname'])
# It is very common to have selectors which retrieve a particular attribute
# from an object or index into the object using a particular key. In these
# cases Python's lambda syntax can seem quite clunky. To mitigate this, asq
# provides two factory functions called a_() and k_() which concisely generate
# selector functions for attributes and keys respectively. The previous
# example could thus be rendered as::
query(students).order_by(k_('lastname')).then_by(k_('firstname'))
def test_k_negative(self):
d = {'sheila': 56, 'jim': 23, 'fred': 55}
foo_selector = k_('foo')
self.assertRaises(KeyError, lambda: foo_selector(d))
def test_k_result_is_callable(self):
foo_selector = k_('foo')
self.assertTrue(is_callable(foo_selector))
def test_k_positive(self):
d = {'sheila': 56, 'jim': 23, 'fred': 55}
jim_selector = k_('jim')
self.assertEqual(jim_selector(d), 23)
dict(firstname='John', lastname='Doe', scores=[34, 12, 92, 93]),
dict(firstname='Jane', lastname='Doe', scores=[33, 94, 91, 13]),
dict(firstname='Ola', lastname='Nordmann', scores=[98, 23, 98, 87]),
dict(firstname='Kari', lastname='Nordmann', scores=[86, 37, 88, 87]),
dict(firstname='Mario', lastname='Rossi', scores=[37, 95, 45, 18])
]
# Find all students where the first score is over 90
first_over_90 = query(students).where(
lambda student: student['scores'][0] > 90)
# Select the last name of students where the first score is over 90
query(students).where(lambda student: student['scores'][0] > 90) \
.select(lambda student: student['lastname'])
# Compute the maximum of all scores overall
query(students).select_many(lambda student: student['scores']).max()
# Order the students by last name and then by first name
query(students).order_by(lambda x: x['lastname']) \
.then_by(lambda x: x['firstname'])
# It is very common to have selectors which retrieve a particular attribute
# from an object or index into the object using a particular key. In these
# cases Python's lambda syntax can seem quite clunky. To mitigate this, asq
# provides two factory functions called a_() and k_() which concisely generate
# selector functions for attributes and keys respectively. The previous
# example could thus be rendered as::
query(students).order_by(k_('lastname')).then_by(k_('firstname'))
def test_k_result_is_callable(self):
foo_selector = k_('foo')
self.assertTrue(is_callable(foo_selector))
def test_k_negative(self):
d = {'sheila' : 56, 'jim' : 23, 'fred' : 55}
foo_selector = k_('foo')
self.assertRaises(KeyError, lambda: foo_selector(d))
def test_k_positive(self):
d = {'sheila' : 56, 'jim' : 23, 'fred' : 55}
jim_selector = k_('jim')
self.assertEqual(jim_selector(d), 23)