30秒就能學(xué)會一個Python小技巧？

鏈接：https://github.com/30-seconds/30-seconds-of-python

def all_equal(lst):
  return lst[1:] == lst[:-1]

all_equal([1, 2, 3, 4, 5, 6]) # False
all_equal([1, 1, 1, 1]) # True

def all_unique(lst):
  return len(lst) == len(set(lst))

x = [1,2,3,4,5,6]
y = [1,2,2,3,4,5]
all_unique(x) # True
all_unique(y) # False

def bifurcate(lst, filter):
  return [
    [x for i,x in enumerate(lst) if filter[i] == True],
    [x for i,x in enumerate(lst) if filter[i] == False]
  ]

def difference(a, b):
  _b = set(b)
  return [item for item in a if item not in _b]

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

def flatten(lst):
  return [x for y in lst for x in y]

flatten([[1,2,3,4],[5,6,7,8]]) # [1, 2, 3, 4, 5, 6, 7, 8]

def digitize(n):
  return list(map(int, str(n)))

digitize(123) # [1, 2, 3]

from copy import deepcopy
from random import randint

def shuffle(lst):
  temp_lst = deepcopy(lst)
  m = len(temp_lst)
  while (m):
    m -= 1
    i = randint(0, m)
    temp_lst[m], temp_lst[i] = temp_lst[i], temp_lst[m]
  return temp_lst

foo = [1,2,3]
shuffle(foo) # [2,3,1] , foo = [1,2,3]

def clamp_number(num,a,b):
  return max(min(num, max(a,b)),min(a,b))

clamp_number(2, 3, 5) # 3
clamp_number(1, -1, -5) # -1

def byte_size(string):
  return len(string.encode('utf-8'))

byte_size('??') # 4
byte_size('Hello World') # 11

from functools import reduce
import math

def gcd(numbers):
  return reduce(math.gcd, numbers)

gcd([8,36,28]) # 4