pythonのリストの一般的な方法

      
#     
'''
1. append：          
2. clear：         
3. copy：           //               
4. count：                 
5. extend：              ，            。
                。 list1.extend(list2)//      list2  list1         list1   
     list1   3 list2   4             list1        7    list1   
   ,                        extend             
6. index：                     
7. insert：                //        append                
8. pop：            （         ），        
9. remove：                 
10. reverse：             
11. sort：         ，             
'''
from sqlalchemy.sql.expression import false
print("--------append  ---------")
numbers = [1,2,3,4,5]
numbers.append(20)
print(numbers)                      #[1, 2, 3, 4, 5, 20]
numbers.append("hello")
numbers.append([1,2,3])
print(numbers)                      #[1, 2, 3, 4, 5, 20, 'hello', [1, 2, 3]]

print("---------clear  ---------")
names = ["Bill", "Mary"]
print(names)                        #['Bill', 'Mary']
names.clear()
print(names)                        #[]

print("----------copy  ----------")
a = [1,2,3,4,5]
acopy = a
acopy1 = a[:]                       #        
acopy2 = a.copy()
a[3] = "hello"                      #            3       
print(acopy)                        #[1, 2, 3, 'hello', 5]
print(acopy1)                       #[1, 2, 3, 4, 5]
print(acopy2)                       #[1, 2, 3, 4, 5]

print("----------count  -----------")
search = ["he", "new", "he", [1,2,3],"he", "world", "peter",[1,2,3]]
#   “he” search     
print(search.count("he"))           # 3

print(search.count([1,2,3]))        # 2

print(search.count(20))  #              ，  0

print("------extend  ------")

a = [1,2,3]
b = [4,5,6]
a.extend(b)
print(a)                # [1, 2, 3, 4, 5, 6]
a[2] =123
print(a)                # [1, 2, 123, 4, 5, 6]
a = [1,2,3]
b = [4,5,6]

x = a
a = a + b
x[2] = 543
print(a)                # [1, 2, 3, 4, 5, 6]
print(x)                # [1, 2, 543] 

print("------index  ------")
numbers = [5,3,6,8]
print(numbers.index(6))  # 2  6    2 
# print(numbers.index(10))  #              ，     

print("-------insert  -------")
numbers = [1,2,3,4,5]
#numbers.insert(3,"four")   # [1, 2, 3, 'four', 4, 5]
#print(numbers)

#              
numbers[3:3] = ["four"]    #                                       4    
print(numbers)              # [1, 2, 3, 'four', 4, 5]

print("-------pop  -------") # pop：            （         ），        
numbers = [1,2,3]
print(numbers.pop())     #                    3       3
print(numbers.pop(1))    #         1           2
print(numbers)           #      2       1        [1]

print("---------remove  ---------")  # remove：                  
words = ["he", "new", "he","yes"]
words.remove("he")
print(words)               #      ['new', 'he', 'yes']              

print("------reverse  --------")  # reverse：             
numbers = [1,2,3,4,5,6,7]
numbers.reverse()          # [7, 6, 5, 4, 3, 2, 1]            2           
print(numbers)

print("--------sort  -------") # sort：         ，             
numbers = [4,3,1,7,4,83,2,-3]
numbers.sort()      
print(numbers)           # [-3, 1, 2, 3, 4, 4, 7, 83]                       
#               ？
#  1:      copy                   
numbers1 = [4,3,1,7,4,83,2,-3]
numbers2 = numbers[:]          #       
numbers2.sort()
print(numbers1)         # [4, 3, 1, 7, 4, 83, 2, -3]
print(numbers2)         # [-3, 1, 2, 3, 4, 4, 7, 83]

numbers3 = numbers1.copy()     #  copy      
print(numbers3)                # [4, 3, 1, 7, 4, 83, 2, -3]

#  2      sort                      sorted                 
#              ，          
x = [5,4,7,2]
y = sorted(x)
print(x)              # [5, 4, 7, 2]
print(y)               #  [2, 4, 5, 7]

#         

print(sorted("www.baidu.com"))   # ['.', '.', 'a', 'b', 'c', 'd', 'i', 'm', 'o', 'u', 'w', 'w', 'w']
#   askm           

#                  
x = [4,6,2,8,44,56,22]
x.sort(reverse = True)  #     reverse  true     ；    flase           
                                    # reverse：             
print(x)                # [56, 44, 22, 8, 6, 4, 2]
x.sort(reverse = False)
print(x)                    # [2, 4, 6, 8, 22, 44, 56]