"Python3" 04, built-in data structure

1. Convert integer or floating-point numbers in string form to int or float, not int and float functions

in [57]: str1 =  "2468.1357" In [58]: d1  = {"0":0,  "1":1,  "2":2,  "3":3,  "4":4,  "5":5,  "6":6,  "7":7,  "8":8,  "    ...: 9":9}    in [59]: int1,  Float1 = str1.split (".") in [60]: sum1 = 0in [61]: sum2 = 0in [62]: for k,  V in enumerate (int1):     ...:     sum1 += d1[ v] * 10 **  (Len (int1)  - k - 1)     ...: for  i, j in enumerate (FLOAT1):     ...:     sum2  += d1[j] * 10 **  (-(i + 1))     ...: print ( SUM1 + SUM2)     ...: 2468.1357# See the students give ideas 

2. Remove duplicate elements from a list and keep the list in its original order

in [[]: L1 = [1, 3, 5, 7, "a", 7, 3, 1, "A", "B", "AB"]in [[+]: L2 = []in]: For i in L1: ...: If I not in L2: ...: l2.append (i) ...: print (L2) ...: [1, 3, 5, 7, ' A ', ' B ', ' AB ']

3, Number of occurrences of each word in the statistical text

in [170]: str1 =  ' Hello world  i like python i like  python too he he python i     ...:  i  World ' In [171]: l1 = str1.split () in [172]: j = 1in [173]:  d1 = {}in [174]: for x in l1:     ...:      if x not in d1:     ...:          d1[x] = j     ...:      ELSE:     ...:         D1[X]  += 1     ...: print (D1)      ...: for  k in d1:     ...:     print ("The {}  count: {} ". Format(K, d1[k]))      ...:     {' i ': 3,  ' Python ': 1,  ' i ':  1,  ' too ': 1,  ' python ': 2,  ' like ': 2,  ' Hello ': 1,  ' he ':  2,  ' World ': 2}the i count: 3the python count: 1the i  count: 1the too count: 1the python count: 2the like count:  2the hello count: 1the he count: 2the world count: 2# text words, Now I have not learned Io, do not know whether to use string substitution, there is the order of the word can not guarantee, do not know what a good way

4. Convert any integer between 1~4000 to Roman numerals

Roman Numerals are Arabic numerals a digital used before passing in. Roman numerals are numbered using seven Roman letters:

Ⅰ (1), X (10), C (100), M (1000), V (5), L (50), D (500).

Methods of Counting:

2. The same number ligatures, the number represented is equal to the number of these numbers added, such as ⅲ=3;

4. The small number is on the right side of the large number, and the number represented is equal to the number added to the number, such as ⅷ=8, ⅻ=12;

6. The small numbers (limited to Ⅰ, X, and C) are on the left side of the large number, and the number represented is equal to the number of large numbers reduced, such as ⅳ=4, ⅸ=9;

8. Draw a horizontal line on top of a number, indicating that the number adds up to 1,000 times, such as 650) this.width=650; "title=" "height=" "width=" "src=" http://g.hiphotos.baidu.com/ Baike/s%3d15/sign=4412a1aab8096b6385195a550d33e4bf/9358d109b3de9c829f0c9f0a6a81800a18d843cd.jpg "style=" border : 0px; "/> = 5000."

10. D1 = {' 1 ': ' I ', ' 5 ': ' V ', ' Ten ': ' X ', ' + ': ' L ', ' + ': ' C ', ' + ': ' D '} #没有思路,,,,

    
    

"Python3" 04, built-in data structure