4.字符串格式

1. 编写程序，已知字符串s = "AbcDeFGhIJ"，请计算该字符串中小写字母的数量。

   s = 'AbcDeFGhIJ'
   num = 0  # 统计英文字母个数
   for i in range(len(s)):  # 利用字符ASCII码中的位逐个统计
       if "a" <= s[i] <= "z":
           num += 1
   print("小写字母的个数为：%d" % num)
   s = "AbcDeFGhIJ"

   输出结果：

   小写字母的个数为：4

   方法二：

   s = "AbcDeFGhIJ"
   count = 0
   for i in s:
       # print(i, "=", ord(i))
       # print(ord('a'), ord('z'))
       if ord(i) >= 97 and ord(i) <= 122:
           count = count + 1
   
   print("小写字符数量为", count)
   
   
   s = "AbcDeFGhIJ"
   count = 0
   for i in s:
       for j in s.lower():
           if i == j:
               count = count + 1
   print("小写字符数量为", count)

    

2. 编写程序，检查字符串" Life is short. I use python"中是否包含字符串"python"，若包含则替换为"Python"后输出新字符串，否则输出原字符串。

   # coding = utf-8
   # 创建一个字符串circle
   source_string = " Life is short. I use python"
   if 'python' in source_string:
       # 利用replace()方法用子串"Python"代替子串"python"
       print(source_string.replace('python', 'Python'))
   else:
       print(" Life is short. I use python")

   输出结果：

    Life is short. I use Python

3. 现在有个字符串是按照如下格式保存的：“姓名:成绩|姓名:成绩|…..”，例如:张三:90|李四:88|王五:100；要求将字符串变为如下的形式显示：“姓名：张三，成绩：90”，显示后的数据如下图所示，按不同的人员显示。

   # 程序一
   str1 = "张三:90"
   str2 = "李四:88"
   str3 = "王五:100"
   Str = str.split("\\|")
   print("姓名:" + str1.split(":")[0] + ",成绩:" + str1.split(":")[1])
   print("姓名:" + str2.split(":")[0] + ",成绩:" + str2.split(":")[1])
   print("姓名:" + str3.split(":")[0] + ",成绩:" + str3.split(":")[1])
   
   
   # 程序二
   str = "张三:90|李四:88|王五:100"
   print("姓名：", str[0 :2], "成绩：", str[3 :5])
   print("姓名：", str[6 :8], "成绩：", str[9 :11])
   print("姓名：", str[12 :14], "成绩：", str[15 :18])
   
   # 程序三
   str = '张三:90|李四:88|王五:100'
   res = ['姓名:{0},成绩:{1}'.format(x.split(':')[0],x.split(':')[1])
          for x in str.split('|')]
   for x in res:
       print(x)
   # 程序四
   s= "张三:90|李四:88|王五:100"
   s1 = s.split("|")
   for i in s1:
       b = i .split(":")
       print("姓名：{0}， 成绩：{1}".format(b[0], b[1]))

    输出结果：

   姓名:张三,成绩:90
   姓名:李四,成绩:88
   姓名:王五,成绩:100