people = [ 
{ 'name': 'John', "age": 64 }, 
{ 'name': 'Janet', "age": 34 }, 
{ 'name': 'Ed', "age": 24 }, 
{ 'name': 'Sara', "age": 64 }, 
{ 'name': 'John', "age": 32 }, 
{ 'name': 'Jane', "age": 34 }, 
{ 'name': 'John', "age": 99 }, 
]

SELECT * FROM people ORDER by name, age

import operator 
people.sort(key=operator.itemgetter('age')) 
people.sort(key=operator.itemgetter('name'))

from dataclasses import dataclass 
     @dataclass
     classCard: 
      rank: str
      suit: str
      card=Card("Q", "hearts") 
     print(card == card) 
     # True 
     print(card.rank) 
     # 'Q' 
     print(card) 
     Card(rank='Q', suit='hearts')

mylist = [i for i inrange(10)] 
    print(mylist) 
    # [0, 1, 2, 3,4, 5, 6, 7, 8, 9]

squares = [x**2for x inrange(10)] 
    print(squares) 
    # [0, 1, 4, 9,16, 25, 36, 49, 64, 81]

defsome_function(a): 
        return (a +5) /2
         
       my_formula= [some_function(i) for i inrange(10)] 
       print(my_formula) 
       # [2.5, 3.0,3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0]

filtered = [i for i inrange(20) if i%2==0] 
    print(filtered) 
    # [0, 2, 4, 6,8, 10, 12, 14, 16, 18]

import sys 
     mylist =range(0, 10000) 
   print(sys.getsizeof(mylist)) 
   # 48

import sys 
     myreallist = [x for x inrange(0, 10000)] 
   print(sys.getsizeof(myreallist)) 
   # 87632

test = [1, 2, 3, 4, 2, 2, 3, 1, 4, 4, 4] 
  print(max(set(test), key = test.count)) 
  # 4

from collections import Counter 
Counter(test).most_common(1) 
# [4: 4]

@attrs
   classPerson(object): 
    name =attrib(default='John') 
    surname =attrib(default='Doe') 
    age =attrib(init=False) 
    p =Person() 
   print(p) 
   p=Person('Bill', 'Gates') 
   p.age=60
   print(p) 
     # Output: 
   # Person(name='John', surname='Doe',age=NOTHING) 
   # Person(name='Bill', surname='Gates', age=60)

dict1 = { 'a': 1, 'b': 2 } 
  dict2= { 'b': 3, 'c': 4 } 
  merged= { **dict1, **dict2 } 
  print (merged) 
  # {'a': 1, 'b':3, 'c': 4}

merged = dict1 | dict2

defget_user(id): 
      # fetch user from database 
      # .... 
      return name, birthdate 
     name, birthdate =get_user(4)

original_list = [ 1，2，3，4，5]#定義列表
  
#定義過濾函數(shù)
4 def filter_three(number):5
  return number > 3
    
filtered = filter(filter_three, original_list)
filtered_list = list(filtered)
filtered_list
  
#[4，5]

original_list = [1,2,3,4,5]2
filtered_list = [ number for number in original_list if number > 3]#在列表推導(dǎo)過程中引入條件判斷
print(filtered_list)
  
#[4，5]

original_list = [1,2,3,4,5]
def square( number):
    return number **2
squares =map(square, original_list)
squares_list = list( squares)
print(squares_list) 
  
#[1，4，9，16，25]

original_list = [1,2,3,4,5]
squares_list = [number ** 2for number in original_list]
print(squares_list)
  
#[1，4,9, 16，25]

numbers = [ 1,2,3]
letters = [ 'a', 'b', 'c']
combined = zip(numbers，letters)
combined_list = list( combined)
print(combined_list)
for item in zip( numbers,letters ):
    print(item[0], '\t', item[1])
      
#[(1，'a')，(2，'b')，(3， 'c')]
#1        a
#2        b
#3        c

original_list = [1,2,3,4,5]

reversed_list = original_list[ : : -1]

print('翻轉(zhuǎn)前: ', original_list)
print('翻轉(zhuǎn)后:', reversed_list)
  
#翻轉(zhuǎn)前:[ 1，2，3，4，5]
#翻轉(zhuǎn)后:[5,4，3，2，1]

games = [ 'Yankees ', 'Yankees ', 'Cubs ', 'Blue Jays ', 'Giants ']
def isin(item，list_name) :
    if item in list_name: print(f"{item} is in the list! ")
    else: print(f"{item} is not in the list! ")

isin( 'Blue Jays ' , games)
isin( ' Angels', games)

#Blue Jays is in the list!
#Angels is not in the list!

nested_list = [[1，2，3]，[4，5，6]，[7，8，9]]

flat_list = [i for j in nested_list for i in j]

print(flat_list)

#[1，2，3，4，5，6，7，8，9]

import tree

nested_list_2d = [[1，2，3]，[4，5，6]，[7，8，9]]

nested_list_3d = [[[1，2]，[3，4]]，
                          [[5，6]，[7，8]]，
                          [[9，10]，[11，12]]]
                           
print(tree.flatten(nested_list_2d))
print(tree.flatten(nested_list_3d))

#[1，2，3，4，5，6，7，8，9]
#[1，2，3，4，5，6，7,，8, 9， 10， 11，12]

list1 = [ 1，2，3，4，5]
list2 = [1，1，2，3，4]

def isunique( 1):
    if len(l) == len(set(l)) :
       print( 唯一! ')
    eise: print(('不唯—! ')
 
isunique( list1)
isunique(list2)

#唯—!
#不唯—!