#正向取
str1='hello tank!'
print(str1[0]) #h
print(str1[9]) #k#反向取
str1='hello tank!'
print(str1[-2]) #k
print(str1[-11]) #h

str1='hello tank!'
print(str1[0:5]) #hello
#0-(5-1)#步长
str1='hello tank!'
print(str1[0:11]) #hello tank!
print(str1[0:11:2]) #hlotn！ 每间隔2个步长取数

str1='hello tank'
print(len[str1]) #11

str1='hello tank'
print('h' in str1) #True
print('h' not in str1) #False

#会移除字符串中左右两边的空格
str1='  hello tank!'
prink(str1)
str1='  hello tank!  '
print(str1)
print(str1.strip())#去除指定字符串
str2='!tank!'
print(str2.strip('!'))

str1='hello tank!'#根据str1内的空格进行切分#切分出来的值会存放在[]列表中
print(str1.split(' '))#['hello','tank!']

#对str1字符串进行遍历，打印每一个字符
str1=’hello tank!'
for line in str1:print(line)

str1 = '  hello wuyuefeng   '
print(str1)
# 去掉两边空格
print(str1.strip())
# 去掉左边空格
print(str1.lstrip())
# 去掉右边空格
print(str1.rstrip())

 str1 = 'hello WuYueFeng'
# 转换成小写print(str1.lower())
# 转换成大写
print(str1.upper())

 str1 = 'hello WuYueFeng'
#  判断str1字符开头是否等于helloprint(str1.startswith('hello'))  # True
#  判断str1字符末尾是否等于WuYueFeng
print(str1.endswith('WuYueFeng'))  # True

str1 = 'my name is %s, my age %s!' % ('tank', 18)
print(str1)
# 方式一:  根据位置顺序格式化print('my name is {}, my age {}!'.format('tank', 18))
# 方式二:  根据索引格式化
print('my name is {0}, my age {1}!'.format('tank', 18))
# 方式三:  指名道姓地格式化
print('my name is {name}, my age {age}!'.format(age=18, name='tank'))

# 报错，只允许字符串拼接print(' '.join(['tank', 18]))
# 根据空格，把列表中的每一个字符串进行拼接
print(' '.join(['tank', '18', 'from GZ']))
# 根据_，把列表中的每一个字符串进行拼接print('_'.join(['tank', '18', 'from GZ']))

str1 = 'my name is WangWei, my age 73!'
print(str1)
str2 = str1.replace('WangWei', 'sb')
print(str2)

choice = input('请选择功能[0, 1, 2]: ')
# 判断用户输入的选择是否是数字
print(choice.isdigit())

'''
字符串格式化输出
%s
%d
'''
# 把100替换给了%s
# str1 = '尊敬的用户，你好！您本月的话费扣除%s元，还剩0元。' % 100# 把一百替换给了%s, 把50替换给了%d
# str1 = '尊敬的用户，你好！您本月的话费扣除%s元，还剩%d元。' % ('一百', 50)
# print(str1)# 报错
str1 = '尊敬的用户，你好！您本月的话费扣除%s元，还剩%d元。' % ('一百', '50')
print(str1)

name = " aleX"
print(name)
print(name.strip())

name = " aleX"
print(name)
print(name.startswith('al'))

name = " aleX"
print(name)
print(name.endswith('X'))

name = " aleX"
print(name)
name1= name.replace("l","p")
print(name1)

name = " aleX"
print(str1.split('l'))

name = " aleX"
print(name.upper())

name = " aleX"
print(name.lower())

name = " aleX"
print(name[2]) 

name = " aleX"
print(name[0：3]) 

name = " aleX"
print(name[-1：-3])

name = " aleX"
print(name.find('e'))

name = " aleX"
print(name[0:4])