a = [x for x in range(int(1e5))]
b = (x for x in range(int(1e5)))
x = a.__sizeof__()
y = b.__sizeof__()

values = ['1', '-3', 'N/A']
def f(val):
    try:
        x = int(val)
        return True
    except ValueError:
        return False
    
vals = list(filter(f, values))
print(vals)

values = ['1', '-3', 'N/A']
def f(val):
    try:
        x = int(val)
        return True
    except ValueError:
        return False
    
vals = list(filter(f, values))
print(vals)

from itertools import compress
x = [1, 2, 3, 4]
y = compress(x, map(lambda i: i & 1, x))
print(*y)

from itertools import compress
x = [1, 2, 3, 4]
y = compress(x, map(lambda i: i & 1, x))
print(*y)

x = {'a' : 1, 'b' : 2, 'c': 3}
y = {t for t in x if t != 'b'}
z = { key:value for key,value in x.items() if key in y }
print(sum(z.values()))

x = {'a' : 1, 'b' : 2, 'c': 3}
y = {t for t in x if t != 'b'}
z = { key:value for key,value in x.items() if key in y }
print(sum(z.values()))

x = {'a' : 1, 'b' : 2, 'c': 3}
y = {t for t in x if t != 'a'}
z = {key:x[key] for key in x.keys() & y}
print(sum(z.values()))

x = {'a' : 1, 'b' : 2, 'c': 3}
y = {t for t in x if t != 'a'}
z = {key:x[key] for key in x.keys() & y}
print(sum(z.values()))

from collections import namedtuple
Uni = namedtuple('Uni', ['num_student', 'num_groups'])
a = [(10, 4), (5, 3), (9, 5)]
def f(records):
    res = 0.0
    for r in records:
        s = Uni(*r)
        res += s.num_student * s.num_groups
    return res
print(f(a))

from collections import namedtuple
A = namedtuple('A', ['x', 'y', 'z'])
a = A(1, 2, 3)
d = dict(x=1, y=2, z=3)
sa = a.__sizeof__()
sd = d.__sizeof__()