#coding: pythonql

def q1_test():

res = [ select (x,y)

for x in range(1,8)

for y in range(1,7)

if x % 2 == 0 and

y % 2 != 0 and

x > y ]

assert res[0].x == 2 and res[0].y == 1

def q2_test():

res = [ (x, sum(y) as sum)

for x in range(1,8),

y in range(1,7)

if x % 2 == 0 and y % 2 != 0 and x > y

group by x ]

assert res[0].x==2 and res[0].sum==1

def q3_test():

res = [ select (x, sum_y)

for x in range(1,8),

y in range(1,7)

where x % 2 == 0 and y % 2 != 0 and x > y

group by x

let sum_y = sum(y)

where sum_y % 2 != 0

]

assert res[0].x==2 and res[0].sum_y==1

assert res[1].x==6 and res[1].sum_y==9

def q4_test():

res = [ (x,y)

for x in range(1,10)

let ys = [ y for y in range(1,10)

where x%2 == 0 and x > y ],

ys_and_none = ys if ys != [] else [ None ]

for y in ys_and_none ]

assert res[3].x==4 and res[3].y==1

assert res[6].x==5 and res[6].y == None

def q5_test():

res = [ select (x,y)

for x in range(1,5),

y in range(1,5)

where x > y

group by x ]

assert res[2].x==4 and res[2].y==[1,2,3]

def q6_test():

res = [ select (x_squared, y)

for x in range(1,5),

y in range(1,5)

where x > y

group by x**2 as x_squared

order by x_squared ]

assert res[2].x_squared==16 and res[2].y==[1,2,3]

assert res[1].x_squared==9 and res[1].y==[1,2]

def q7_test():

res = [ select (x,y)

for x in range(1,5),

y in range(1,5)

where x > y

order by abs(x-y) asc, y desc ]

assert res[0].x==4 and res[0].y==3

assert res[1].x==3 and res[1].y==2

def q8_test():

db = [ {"region": [{"box": [1,2], "label":"lake" },

{"box": {"box": [2,3]} },

{"region": {"box":[ 1,2], "label":"lake"} },

{"region": {"circle": [0.5,0.5,45], "label":"pond" }}] },

{"region": {"box": [1,2], "label":"lake" }}]

assert len(list(db./'region'./'region'))==2

assert len(list(db .// 'box'))==5

def q9_test():

data = [ 15, 25, None, 80, 34, "34", "twenty", [12], 54, 12]

res = sum([ select num

for item in data

let num = try int(item) except 0 ])

assert res == 254

def q10_test():

res = [ select {"sequence_start": i,

"sequence": [ select {"item":k}

for k in range(i,i+5) ]}

for i in [1,3,5]]

assert res[1]['sequence_start']==3 and len(res[1]['sequence'])==5

def q11_test():

x = [1,2,3,4,5,6,7]

res = [ select (y,sum(w) as sum)

for sliding window w in x

start y at s when True

end at e when e-s == 2 ]

assert res[0].y==1 and res[0].sum==6

assert res[1].y==2 and res[1].sum==9

assert res[2].y==3 and res[2].sum==12

def q12_test():

x = [1,2,3,4,5,6,7]

res = [ select (y,sum(w) as sum)

for sliding window w in x

start y when y % 2 == 0

end z when z-y > 2 ]

assert res[0].y==2 and res[0].sum==14

assert res[1].y==4 and res[1].sum==22

assert res[2].y==6 and res[2].sum==13

def q13_test():

res = [ select (s, x)

for sliding window x in

(select (y,z)

for (y,z) in [(1,1), (2,2), (3,3),

(4,4), (5,5), (6,6)])

start s when s.y % 2 == 1

only end e when e.y-s.y >= 2 ]

assert res[0].s.y==1 and res[0].s.z==1

assert res[1].s.y==3 and res[1].s.z==3