2022-08-18 学习Python-Day7

wyh551202

第七天完成list的相关学习，P20~P26

1. 
   
2. ######################## P20
   
3. list=[1,2,3,'aaaa']
   
4. print(list)
   
5. for each in list:
   
6.     print(each)
   
7. 
   
8. list_len=len(list)
   
9. print(list[list_len-1])
   
10. print(list[-1])
    
11. 
    
12. print(list[2:3])
    
13. print(list[2:])
    
14. print(list[:2])
    
15. print(list[0:3:2])
    
16. 
    
17. ######################## P21
    
18. heros=['钢铁侠','绿巨人']
    
19. heros.append('黑寡妇')
    
20. heros.extend(['鹰眼','灭霸'])
    
21. 
    
22. s=[1,2,3,4,5]
    
23. s[len(s):] = [7,8,9]
    
24. print(s)
    
25. s=[1,3,4,5]
    
26. s.insert(1,2)
    
27. s.insert(0,0)
    
28. s.insert(len(s),6)
    
29. print(s)
    
30. heros.remove('灭霸')
    
31. heros.pop(2)
    
32. heros.clear()
    
33. print(heros)
    
34. ######################## P22
    
35. heros=['蜘蛛侠','绿巨人','黑寡妇','鹰眼','灭霸','雷神']
    
36. heros[0]='钢铁侠'
    
37. heros[3:]=['武松','林冲','李逵']
    
38. print(heros)
    
39. nums=[3,1,9,6,8,3,5,3]
    
40. nums.sort()
    
41. nums.reverse()
    
42. print(nums)
    
43. nums=[3,1,9,6,8,3,5,3]
    
44. nums.sort(reverse=True)
    
45. print(nums)
    
46. nums_3=nums.count(3)
    
47. print(nums_3)
    
48. heros_lv=heros.index("绿巨人")
    
49. print(heros_lv)
    
50. heros[heros.index("绿巨人")]='神奇女侠'
    
51. print(heros)
    
52. nums=[3,1,9,6,8,3,5,3]
    
53. nums_index_3=nums.index(3,1,7)
    
54. print(nums_index_3)
    
55. nums_copy1=nums.copy()
    
56. nums_copy2=nums[:]
    
57. 
    
58. ######################## P23
    
59. s=[1,2,3]
    
60. t=[4,5,6]
    
61. st=s+t
    
62. s3=s*3
    
63. print(st)
    
64. print(s3)
    
65. matrix=[[1,2,3],
    
66.         [4,5,6],
    
67.         [7,8,9]]
    
68. for i in matrix:
    
69.     print(i)
    
70.     for each in i:
    
71.         print(each,end=' ')
    
72.     print()
    
73. print(matrix[0][0])
    
74. A=[0]*3
    
75. for i in range(3):
    
76.     A[i]=[0]*3
    
77. B=[[0]*3]*3
    
78. 
    
79. A[1][1]=1
    
80. B[1][1]=1
    
81. print(A)
    
82. print(B)
    
83. x='cccc'
    
84. y='cccc'
    
85. xy=(x is y)
    
86. print(xy)
    
87. x=[1,2,3]
    
88. y=[1,2,3]
    
89. xy=(x is y)
    
90. print(xy)
    
91. ######################## P24
    
92. x=[1,2,3]
    
93. y=x
    
94. x[1]=1
    
95. print(x)
    
96. print(y)
    
97. x=[1,2,3]
    
98. y=x.copy()
    
99. x[1]=1
    
100. print(x)
     
101. print(y)
     
102. x=[1,2,3]
     
103. y=x[:]
     
104. x[1]=1
     
105. print(x)
     
106. print(y)
     
107. 
     
108. x=[[1,2,3],
     
109.    [4,5,6],
     
110.    [7,8,9]]
     
111. y=x.copy()
     
112. x[1][1] =0
     
113. print(x)
     
114. print(y)
     
115. 
     
116. import copy
     
117. x=[[1,2,3],
     
118.    [4,5,6],
     
119.    [7,8,9]]
     
120. y=copy.deepcopy(x)
     
121. x[1][1] =0
     
122. print(x)
     
123. print(y)
     
124. ######################## P25
     
125. oho=[1,2,3,4,5]
     
126. for i in range(len(oho)):
     
127.     oho[i]=oho[i]*2
     
128. print(oho)
     
129. oho=[1,2,3,4,5]
     
130. oho=[i*2 for i in oho]
     
131. print(oho)
     
132. x=[i+1 for  i in range(10) ]
     
133. print(x)
     
134. y=[c*2 for c in 'FishC']
     
135. print(y)
     
136. code=[ord(c) for c in 'FishC']
     
137. print(code)
     
138. 
     
139. matrix=[[1,2,3],
     
140.         [4,5,6],
     
141.         [7,8,9]]
     
142. col2=[row[1] for row in matrix]
     
143. print(col2)
     
144. diag=[matrix[i][i] for i in range(len(matrix))]
     
145. print(diag)
     
146. 
     
147. diag=[matrix[i][len(matrix)-1-i] for i in range(len(matrix))]
     
148. print(diag)
     
149. 
     
150. ######################## P26
     
151. B=[[0]*3] *3
     
152. B[1][1] =1
     
153. print(B)
     
154. A=[0]*3
     
155. for i in range(3):
     
156.     A[i]=[0]*3
     
157. A[1][1] =1
     
158. print(A)
     
159. s=[[0]*3 for i in range(4)]
     
160. print(s)
     
161. even=[i for  i in range(10) if i%2==0 ]
     
162. print(even)
     
163. even=[i+1 for  i in range(10) if i%2==0 ]
     
164. print(even)
     
165. words=['Great','FishC','Brilliant','Excellent','Fantistic']
     
166. word_F=[i for i in words if i[0]=='F' ]
     
167. print(word_F)
     
168. matrix=[[1,2,3],
     
169.         [4,5,6],
     
170.         [7,8,9]]
     
171. flatten=[col for row in matrix
     
172.              for col in  row]
     
173. print(flatten)
     
174. flatten=[]
     
175. for row in matrix:
     
176.     for col in row:
     
177.         flatten.append(col)
     
178. print('s',flatten)
     
179. z=[x+y for x in 'fishc'
     
180.        for y in 'FISHC']
     
181. print(z)
     
182. 
     
183. z=[[x,y] for x in range(10) if x%2==0
     
184.            for y in range(10) if y%3==0]
     
185. print(z)
     
186. z=[]
     
187. for x  in range(10):
     
188.     if x%2 ==0:
     
189.         for y in range(10):
     
190.             if y%3==0:
     
191.                 z.append([x,y])
     
192. print('w',z)
     
193.         
     
194.    
     

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wyh551202

我觉得列表表达式，换行容易理解
z=[[x,y] for x in range(10) if x%2==0
           for y in range(10) if y%3==0]
要比
z=[[x,y] for x in range(10) if x%2==0 for y in range(10) if y%3==0]
容易看出