print('a'.isalpha())
## True

print('한글'.isalpha())
## True

print(3.isdigit())
## True

points =[(2, 2), (0, 3), (1, 1), (4, 1)]
points.sort(key=lambda x: x[0])
print(points)

## [(0, 3), (1, 1), (2, 2), (4, 1)]

import math
a = math.inf
print(a)
## inf
print(-math.inf)
## -inf

from itertools import permutations, combinations

my_list = ['1', '2', '3', '4']
perm = permutations(my_list,2)
print(list(perm))

comb = combinations(my_list,2)
print(list(comb))
## [('1', '2'), ('1', '3'), ('1', '4'), ('2', '1'), ('2', '3'), ('2', '4'), ('3', '1'), ('3', '2'), ('3', '4'), ('4', '1'), ('4', '2'), ('4', '3')]
## [('1', '2'), ('1', '3'), ('1', '4'), ('2', '3'), ('2', '4'), ('3', '4')]

alpha = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
list_alpha = [ (alpha[k],k) if k<=13 else (alpha[k],26-k) for k in range(len(alpha))   ]   # list comprehension 으로 list생성
dict_alpha = dict(list_alpha) # dictionary