python学习5—一些关于基本数据结构的练习题

python学习5—一些关于基本数据结构的练习题

 # 1. use _ to connect entries in a list
 # if there are no numbers in list
 li = ['alex','eric','rain']
 v = '_'.join(li)
 print(v)
 # if there are numbers in list
 li = ['alex','eric',123]
 nli = []  # initialize a list new li (nli)
 for item in li:
     nli.append(str(item))  # add strred entries into list s
 v = "_".join(nli)
 print(nli,v)

 # 3. for a list
 li = ['alex','eric','rain']
 # realize the following functions:
 # a. figure out the length of tuple and output the result
 print(len(li))
 # b. add "seven" into the list
 li.append('seven')
 print(li)
 # c. insert "Tony" at the first place
 li.insert(0,'Tony')
 print(li)
 # d. insert "Kelly" at the second place
 li.insert(1,'Kelly')
 print(li)
 # e. delete "eric"
 li.remove('eric')
 print(li)
 ## f. delete the second entry, output the entry deleted
 #v = li.pop(1)
 #print(v,li)
 ## g. delete the third entry, output the list
 #li.pop(2)
 #print(li)
 ## h. delete the entries from 2 to 4, output the list
 #del li[1:4]
 #print(li)
 # i. reverse the list
 li.reverse()
 print(li)
 # j. use for, len, range to output the index of the list
 for i in range(len(li)):
     print(i)
 # k. use enumerate to output entries and index from 100
 for idx, elem in enumerate(li,100):
     print(idx,elem)
 # l. use for to output all the entries
 for item in li:
     print(item)

 # 4. 

 # 5. for a tuple
 tu = ('alex','eric','rain')
 # realize the following functions:
 # a. figure out the length of tuple and output the result
 print(len(tu))
 # b. obtain the 2nd entry of the tuple and output it
 print(tu[1])
 # c. obtain the entries from 1 to 2 and output them
 print(tu[0:2])
 # d. use for to output all the entries of the tuple
 for item in tu:
     print(item)
 # e. use for, len, range to output the index of the tuple
 for i in range(0,len(tu)):
     print(i)
 # f. use enumrate output the entries and index of the tuple,
 # the index beginning at 10
 for idx, elem in enumerate(tu,10):
     print(idx,elem)

 # 6. for a tuple
 tu = ("alex",[11,22,{"k1":'v1',"k2":["age","name"],"k3":(11,22,33)},44])
 # add an entry in the value corresponding to "k2" if addable
 tu[1][2]["k2"].append("Seven")
 print(tu)

 # 10. output goods list, costoms input the number and show the good w.r.t the index
 li = ['iphone','laptop','cup','ship']
 idx = 1
 while idx > 0:
     good = input('please input the good added:')
     if bool(good):
         li.append(good)
     idx = int(input('please input the number of the good:'))
     print(li[idx-1])

 # 12. False in bool: 3 + 3 + 1
 # {}, [], ()
 # 0, "", False
 # None

 # 13. there are two lists:
 l1 = [11,22,33]
 l2 = [22,33,44]
 # a. obtain the same entries of the two lists
 for i in l1:
     if i in l2:
         print(i)
 # b. obtain the entries in l1 not in l2
 for i in l1:
     if i not in l2:
         print(i)
 # c. obtain the entries in l2 not in l1
 for i in l2:
     if i not in l1:
         print(i)
 # d. obtain the entries that different in l1 and l2
 for i in l1:
     if i not in l2:
         print(i)
 for i in l2:
     if i not in l1:
         print(i)

 # 16. display contents in different pages, one page with 10 items
 user_list = []
 for i in range(1,302):
     temp = {'name':'alex'+str(i),'email':'alex@alex.com'+str(i)}
     user_list.append(temp)

 page = 1
 while page > 0 and page < 32:
     page = int(input('please input the page you want to look:'))
     start = (page - 1)*10
     end = page * 10
     result = user_list[start:end]
     for item in result:
         print(item)

 # 17. the numbers of combanions of two numbers in 1-8, and the two digits are different
 li = [1,2,3,4,5,6,7,8]
 count = 0
 l = len(li)
 for i in range(l):
     for j in range(l):
         if i != j:
             count += 1
 print(count)
 # 18. output 9*9 table
 for i in range(1,10):
     for j in range(i,10):
         print(i,'*',j,'=',i*j,end = '\t')
     print('')

 # 19. for a list
 nums = [2,7,11,15,1,8,7]
 # find the pairs that the sum of which is 9
 l = len(nums)
 li = []
 for i in range(l):
     for j in range(i+1,l):
         if nums[i] + nums[j] == 9:
             li.append((nums[i],nums[j],))
 print(li)

 # 20. a costs 5 yuan, b costs 3 yuan, 3c costs 1 yuan
 #   use 100 yuan to buy 100 entities, give solutions
 for x in range(1,100//5):
     for y in range(1,100//3):
         for z in range(1,100):
             if x + y + z == 100 and 5*x + 3*y + z/3 == 100:
                 print(x,y,z)

 # end of file