from collections import ChainMap
a = {'x': 1, 'z': 3 }
b = {'y': 2, 'z': 4 }
c = ChainMap(a,b)
print(c['x'] + c['y'] - c['z'])

from collections import ChainMap
d1 = {'x': 1, 'z': 10}
d2 = {'y': 2, 'z': 20}
d3 = {**d1, **d2}
d4 = ChainMap(d1, d2)
s1 = d3['x'] + d3['y'] + d3['z']
s2 = d4['x'] + d4['y'] + d4['z']
print(s1, s2)

from collections import ChainMap
a = {'x': 1, 'z': 3 }
b = {'y': 2, 'z': 4 }
c = ChainMap(a,b)
c['z'] = 10
c['w'] = 40
del c['x']
print(sum(a.values()), sum(b.values()))

from collections import ChainMap
a = {'x': 1}
b = {'x': 2}
c = {'x': 3}
d = ChainMap(a, b, c)
del d['x']
del d['x']
print(d['x'])

from collections import ChainMap
values = ChainMap()
values['x'] = 1
values = values.new_child()
values['x'] = 2
values = values.parents
print(values['x'])

from collections import ChainMap
a = {'x': 1, 'z': 3 }
b = {'y': 2, 'z': 4 }
c = ChainMap(a, b)
a['x'] = 10
c['y'] = 20
c['z'] = 30 
print(c['x'], b['y'], a['z'], b['z'])

import re
line = "a+b"
x = re.split(r"(\+)", line)
y = re.split(r"\+", line)
z = re.split(r"(?:\+)", line)
p = set(x) - set(y) | set(z)
print(len(p))

from fnmatch import fnmatch
n = "foo2022.txt"
x = fnmatch(n, "foo[0-9]*")
y = fnmatch(n, "foo[0-9]+")
print(x, y)

from fnmatch import fnmatchcase
l = [f'{b}{a}' for a in range(20) for b in ['x', 'y']]
r = [x for x in l if fnmatchcase(x, 'x*0')]
print(*r)