1 # 1. use _ to connect entries in a list
2 # if there are no numbers in list
3 li = ['alex','eric','rain']
4 v = '_'.join(li)
5 print(v)
6 # if there are numbers in list
7 li = ['alex','eric',123]
8 nli = [] # initialize a list new li (nli)
9 for item in li:
10 nli.append(str(item)) # add strred entries into list s
11 v = "_".join(nli)
12 print(nli,v)
13
14 # 3. for a list
15 li = ['alex','eric','rain']
16 # realize the following functions:
17 # a. figure out the length of tuple and output the result
18 print(len(li))
19 # b. add "seven" into the list
20 li.append('seven')
21 print(li)
22 # c. insert "Tony" at the first place
23 li.insert(0,'Tony')
24 print(li)
25 # d. insert "Kelly" at the second place
26 li.insert(1,'Kelly')
27 print(li)
28 # e. delete "eric"
29 li.remove('eric')
30 print(li)
31 ## f. delete the second entry, output the entry deleted
32 #v = li.pop(1)
33 #print(v,li)
34 ## g. delete the third entry, output the list
35 #li.pop(2)
36 #print(li)
37 ## h. delete the entries from 2 to 4, output the list
38 #del li[1:4]
39 #print(li)
40 # i. reverse the list
41 li.reverse()
42 print(li)
43 # j. use for, len, range to output the index of the list
44 for i in range(len(li)):
45 print(i)
46 # k. use enumerate to output entries and index from 100
47 for idx, elem in enumerate(li,100):
48 print(idx,elem)
49 # l. use for to output all the entries
50 for item in li:
51 print(item)
52
53 # 4.
54
55 # 5. for a tuple
56 tu = ('alex','eric','rain')
57 # realize the following functions:
58 # a. figure out the length of tuple and output the result
59 print(len(tu))
60 # b. obtain the 2nd entry of the tuple and output it
61 print(tu[1])
62 # c. obtain the entries from 1 to 2 and output them
63 print(tu[0:2])
64 # d. use for to output all the entries of the tuple
65 for item in tu:
66 print(item)
67 # e. use for, len, range to output the index of the tuple
68 for i in range(0,len(tu)):
69 print(i)
70 # f. use enumrate output the entries and index of the tuple,
71 # the index beginning at 10
72 for idx, elem in enumerate(tu,10):
73 print(idx,elem)
74
75 # 6. for a tuple
76 tu = ("alex",[11,22,{"k1":'v1',"k2":["age","name"],"k3":(11,22,33)},44])
77 # add an entry in the value corresponding to "k2" if addable
78 tu[1][2]["k2"].append("Seven")
79 print(tu)
80
81 # 10. output goods list, costoms input the number and show the good w.r.t the index
82 li = ['iphone','laptop','cup','ship']
83 idx = 1
84 while idx > 0:
85 good = input('please input the good added:')
86 if bool(good):
87 li.append(good)
88 idx = int(input('please input the number of the good:'))
89 print(li[idx-1])
90
91 # 12. False in bool: 3 + 3 + 1
92 # {}, [], ()
93 # 0, "", False
94 # None
95
96 # 13. there are two lists:
97 l1 = [11,22,33]
98 l2 = [22,33,44]
99 # a. obtain the same entries of the two lists
100 for i in l1:
101 if i in l2:
102 print(i)
103 # b. obtain the entries in l1 not in l2
104 for i in l1:
105 if i not in l2:
106 print(i)
107 # c. obtain the entries in l2 not in l1
108 for i in l2:
109 if i not in l1:
110 print(i)
111 # d. obtain the entries that different in l1 and l2
112 for i in l1:
113 if i not in l2:
114 print(i)
115 for i in l2:
116 if i not in l1:
117 print(i)
118
119 # 16. display contents in different pages, one page with 10 items
120 user_list = []
121 for i in range(1,302):
122 temp = {'name':'alex'+str(i),'email':'alex@alex.com'+str(i)}
123 user_list.append(temp)
124
125 page = 1
126 while page > 0 and page < 32:
127 page = int(input('please input the page you want to look:'))
128 start = (page - 1)*10
129 end = page * 10
130 result = user_list[start:end]
131 for item in result:
132 print(item)
133
134 # 17. the numbers of combanions of two numbers in 1-8, and the two digits are different
135 li = [1,2,3,4,5,6,7,8]
136 count = 0
137 l = len(li)
138 for i in range(l):
139 for j in range(l):
140 if i != j:
141 count += 1
142 print(count)
143 # 18. output 9*9 table
144 for i in range(1,10):
145 for j in range(i,10):
146 print(i,'*',j,'=',i*j,end = ' ')
147 print('')
148
149 # 19. for a list
150 nums = [2,7,11,15,1,8,7]
151 # find the pairs that the sum of which is 9
152 l = len(nums)
153 li = []
154 for i in range(l):
155 for j in range(i+1,l):
156 if nums[i] + nums[j] == 9:
157 li.append((nums[i],nums[j],))
158 print(li)
159
160 # 20. a costs 5 yuan, b costs 3 yuan, 3c costs 1 yuan
161 # use 100 yuan to buy 100 entities, give solutions
162 for x in range(1,100//5):
163 for y in range(1,100//3):
164 for z in range(1,100):
165 if x + y + z == 100 and 5*x + 3*y + z/3 == 100:
166 print(x,y,z)
167
168 # end of file