字符串内置方法

s = 'hello'
print(s[1])

s='hello how are you'
print(s[0:4])#顾头不顾尾
print(s[0:4:2])#2表示步长，隔一个取一个
print(1,s[4:0:-1])# +从左到右，-表示从右到左
print(1,s[2:])# 左边的不写取到最左边，右边的不写取到最右边

for i in s:
    print(4,i)

s='hello how are you'
print('hello' in s)
print('hello1' not in s)

s1 = '   juary     ***'
print(s1.strip(' j*'))

s1 = 'hello|how|are|you'
print(s1.split('|'))# 按照|切割字符串，得到的是一个列表

s='hello how are you'
print(len(s))

s2='**hello**'
print(s2.lstrip('*'))#去掉左边的'*'
print(s2.rstrip('*'))#去掉右边的'*'

s3='xiaomei'
print(s3.lower())#小写
print(s3.upper())#大写

s='hello how are you'
print(s.startswith('hell'))#以。。。开始
print(s.endswith('you'))#以。。。结束，如果是则返回True,否则返回False

s1 = 'hello|how|are|you'
print(s1.split('|',1))#从左切割
print(s1.rsplit('|',1))#从右切割

s1 = 'hello|how|are|you'
lt = s1.split('|')
print(lt)
print('*'.join(lt))#使用*拼接列表内的每一个元素

s='hello how are you'
s=s.replace('hello','hai')
print(s)

s='123456s'
print(s.isdigit())#判断字符串内字符是否都为数字，返回bool值
print(s.isalpha())#判断字符串内字符是否都为字母，返回bool值

s='hello how are you'
print(s.find('h'))#查找索引，没有找到返回-1
print(s.rfind('h',4,10))#(print(s,rfind))#(4,10)为在索引从（4，10）索引内查找

s5 = 'aaasssaaa'
print(s5.count('a'))#统计a的个数

s = 'hai'
print(s.center(50,'*'))#居中
print(s.ljust(50,'*'))#居左
print(s.rjust(50,'*'))#居右
print(s.zfill(9))#往字符串内左侧填充0，填充到一共9个字符

S = "this is\tstring example....wow!!!"
 
print ("原始字符串: " + S)
print ("替换 \\t 符号: " +  S.expandtabs())
print ("使用16个空格替换 \\t 符号: " +  S.expandtabs(16))

s='hello how are you'
print(s.capitalize())#首字母大写
print(s.swapcase())#所有字母小写变大写，大写变小写
print(s.title())#每个单词的首字母大写