i=8
print(i.bit_length())

# int ---> str
i = 1
s = str(i)
# str ---> int
s = ‘123‘
i = int (s)

# int ---> bool
i=3
print(bool(i))

# bool---> int Ture  1 False  0

#str ----> bool
s = ""---->False
s = "0"--->Ture

s = ‘ABCDEFG‘
# 索引
s1 = s[0]
print(s1)#A

s2 =s[-2]
print(s2)# F

# 切片:顾头不顾尾
s = ‘ABCDEFG‘
s3 = s[0:3]
print(s3) # ABC

s4 = s[0:]
print(s4) # ABCDEFG

s5 = s[:]
print (s5)# ABCDEFG

s6 = s[0:5:2]# s[首：尾：步长]
print(s6)#ACE

s7 = s[4::-1]#倒取
print(s7)#EDCBA

s = ‘afwkDjh‘
s1 = s.capitalize() # 首字母大写
print(s1)   #Afwkdjh

# 全大写、全小写
s2 = s.upper()
s3 = s.lower() 
print(s2,s3) # AFWKDJH afwkdjh

# 大小写翻转
s4 = s.swapcase()
print(s4)   # AFWKdJH

#每隔开（特殊字符或数字）的首字母大写
s = ‘sdf dff*kgj-jia‘
s0 = s.title()
print(s0)  # Sdf Dff*Kgj-Jia

#居中，空白填充
s = ‘fiheiFIjifa‘
s5 = s.center(30,‘*‘)
print(s5)
# *********fiheiFIjifa**********

# 字符长度
s = ‘sdidh大哥‘
l = len(s)
print(l)   #7

# 判断是否是开头
s = ‘alsfiffhis‘
s7 = s.startswith(‘a‘)
s8 = s.startswith(‘alsf‘)
s81 = s.startswith(‘s‘,2,5)
print(s7,s8,s81)  # True True True

#  默认去前后空格、也可以指定
s = ‘   &  df#siffk%‘
s1 = s.strip()
print(s1)  #&  df#siffk%

s2 = s.strip(‘%‘)   #   &  df#siffk
s3 = s.strip(‘ &%‘)
print(s2,s3)  #df#siffk

username = input(‘请输入名字：‘).strip()
if username == ‘wws‘:
    print(‘输入正确‘)

# lstrip()删左  rstrip()删右
s = ‘%asua%‘
s1 = s.lstrip(‘%‘)  #asua%
s2 = s.rstrip(‘%‘) #%asua
print(s1,s2)

#计数
s = ‘aasfjajfaidaa‘
s3 = s.count(‘a‘)   #6
s4 = s.count(‘a‘,2,)  #4
print(s3,s4)

#分割文本
s = ‘ajai*hf ahf*a ifhi*shf idf‘
s5 = s.split() #[‘ajai*hf‘, ‘ahf*a‘, ‘ifhi*shf‘, ‘idf‘]
s6 = s.split(‘*‘)#[‘ajai‘, ‘hf ahf‘, ‘a ifhi‘, ‘shf idf‘]
print(s5,s6)

#format的三种玩法 格式化输出
name = "wws"
age = "18"
hobby = ‘ym‘
s =‘我叫{}，今年{}，爱好{},我叫{}‘.format("wws","18",‘ym‘,"wws")
s0 = ‘我叫{0}，今年{1}，爱好{2},我叫{0}‘.format(name,age,hobby)
s1 = ‘我叫{name}，今年{age}，爱好{hobby},我叫{name}‘.format(age = "18",name = "wws",hobby = ‘ym‘)#
print(s,s0,s1)#我叫wws，今年18，爱好ym,我叫wws

# 替换,可指定特换多少个
s = ‘我是一名学生，学生是我‘
s0 = s.replace(‘学生‘,‘老师‘)#我是一名老师，老师是我
s1 = s.replace(‘学生‘,‘老师‘,1)#我是一名老师，学生是我
print(s0,s1) 

s_str = ‘ASdf‘
you_str = input("请输入验证码不区分大小写：")
if s_str.upper() == you_str.upper():
    print(‘验证成功‘)
else:
    print(‘验证错误‘)