Python刷题系列(6)_列表List（下）

my_list = [10, 20, 30, 40, 20, 50, 60, 40]
print("Original List : ",my_list)
my_set = set(my_list)
my_new_list = list(my_set)
print("List of unique numbers : ",my_new_list)
'''
Original List :  [10, 20, 30, 40, 20, 50, 60, 40]
List of unique numbers :  [40, 10, 50, 20, 60, 30]
'''

def second_smallest(numbers):
  if (len(numbers)<2):
    return
  if ((len(numbers)==2)  and (numbers[0] == numbers[1]) ):
    return
  dup_items = set()# 空集合
  uniq_items = []# 空列表
  for x in numbers:
    if x not in dup_items:
      uniq_items.append(x)
      dup_items.add(x)
  uniq_items.sort() #将列表中的元素从小到大进行排序   
  return  uniq_items[1]   
print(second_smallest([1, 2, -8, -2, 0, -2]))
print(second_smallest([1, 1, 0, 0, 2, -2, -2]))
print(second_smallest([1, 1, 1, 0, 0, 0, 2, -2, -2]))
print(second_smallest([2,2]))
print(second_smallest([2]))
'''
-2
0
0
None
None
'''

color = [("Black", "#000000", "rgb(0, 0, 0)"), ("Red", "#FF0000", "rgb(255, 0, 0)"),
         ("Yellow", "#FFFF00", "rgb(255, 255, 0)")]
var1, var2, var3 = color
print(var1)
print(var2)
print(var3)
print(type(var1))
'''
('Black', '#000000', 'rgb(0, 0, 0)')
('Red', '#FF0000', 'rgb(255, 0, 0)')
('Yellow', '#FFFF00', 'rgb(255, 255, 0)')
<class 'tuple'>
'''

color = ['red', 'green', 'orange']
print('-'.join(color))
print(''.join(color))
'''
red-green-orange
redgreenorange
'''

import ast
color ="['Red', 'Green', 'White']"
print(ast.literal_eval(color))  #['Red', 'Green', 'White']

def remove_words(list1, remove_words):
    for word in list(list1):
        if word in remove_words:
            list1.remove(word)
    return list1        
colors = ['red', 'green', 'blue', 'white', 'black', 'orange']
remove_colors = ['white', 'orange']
print("Original list:")
print(colors)
print("\nRemove words:")
print(remove_colors)
print("\nAfter removing the specified words from the said list:")
print(remove_words(colors, remove_colors))
'''
Original list:
['red', 'green', 'blue', 'white', 'black', 'orange']
Remove words:
['white', 'orange']
After removing the specified words from the said list:
['red', 'green', 'blue', 'black']
'''

def l_strs_to_l_chars(lst):
    result = [i for element in lst for i in element]
    return result
colors = ["red", "white", "a", "b", "black", "f"]
print("Original list:")
print(colors)
print("\nConvert the said list of strings and characters to a single list of characters:")
print(l_strs_to_l_chars(colors))
'''
Original list:
['red', 'white', 'a', 'b', 'black', 'f']
Convert the said list of strings and characters to a single list of characters:
['r', 'e', 'd', 'w', 'h', 'i', 't', 'e', 'a', 'b', 'b', 'l', 'a', 'c', 'k', 'f']
'''

def max_min_sublist(lst):
    max_result = (max(lst, key=sum))
    min_result = (min(lst, key=sum))
    return max_result,min_result
nums = [[1,2,3,5], [2,3,5,4], [0,5,4,1], [3,7,2,1], [1,2,1,2]]
print("Original list:")
print(nums)
result = max_min_sublist(nums)
print("\nMaximum sum of sub list of the said list of lists:")
print(result[0])
print("\nMinimum sum of sub list of the said list of lists:")
print(result[1])

def max_occurrences(nums):
    max_val = 0
    result = nums[0] 
    for i in nums:
        occu = nums.count(i)
        if occu > max_val:
            max_val = occu
            result = i 
    return result
nums = [2,3,8,4,7,9,8,2,6,5,1,6,1,2,3,4,6,9,1,2]
print ("Original list:")
print(nums)
print("\nItem with maximum occurrences of the said list:")
print(max_occurrences(nums))

import random
def random_select_nums(n_list, n):
        return random.sample(n_list, n)
n_list = [1,1,2,3,4,4,5,1]
print("Original list:") 
print(n_list)
selec_nums = 3
result = random_select_nums(n_list, selec_nums)
print("\nSelected 3 random numbers of the above list:")
print(result)