Python學習筆記八:字串的操作(二)

 

 1 #coding:utf-8
 2 #兩個小函數
 3 #一、尋找字元在字串中第一次出現的位置.
 4  def find(string, char):
 5     index = 0
 6     while index < len(string):
 7         if (string[index] == char):
 8             return index
 9         index += 1
10     return -1
11 
12  #二、尋找字元在字串中的總數
13  def findSum(string, char):
14     index = 0
15     count = 0
16     while index < len(string):
17         if (string[index] == char):
18             count += 1
19         index += 1
20     return count
21 
22  #使用以上兩個函數
23 print "字元1在字串1211211234中第一次出現的位置: ", find("1211211234", "1")
24 print "字元1在字串1211211234中出現的次數:", findSum("1211211234", "1")
25 
26 import string  #引入string庫
27 print string.find('www.cctv.com', 'com')   #result=9
28 print string.find('Good','d')              #result = 3
29 print string.find('canada', 'a',2,9)       #result =3，用法如下:
30 #string.find(s, sub[, start[, end]])函數說明
31 #Return the lowest index in s where the substring sub is found such that sub is
32 #wholly contained in s[start:end]. Return -1 on failure. Defaults for start and
33 #end and interpretation of negative values is the same as for slices.
34 print string.lowercase                     #常量，abcdefghijklmnopqrstuvwxyz
35 print string.uppercase                     #常量,ABCDEFGHIJKLMNOPQRSTUVWXYZ
36 print string.digits                        #常量，0123456789
37 
38 def isLower(char):                        #判斷一個字元是否為小寫
39     if (string.find(string.lowercase, char) > -1):
40         return 'Good'
41     return 'bad'
42 print isLower('S')
43 
44 def isLowertest(char):                   #另外一種判斷字元是否為小寫方法
45     return  char in string.lowercase
46 print isLowertest('a')
47