a = 'Hello world'

# upper全部大寫

print(a.upper()) ==》HELLO WORLD

# lower全部小寫

print(a.lower())? ==》hello world

# title首字母大寫

print(a.title()) ==》Hello World

# capitalize首字母變大寫

print(a.capitalize())? ?==》Hello world

# swapcase大寫變小寫。小寫變大寫

print(a.swapcase())?

# count統(tǒng)計(jì)字符出現(xiàn)的次數(shù)

print(a.count('o')) ==》2

# replace替換字符

b= a.replace('world','python')

print(b) ==》Hello python

# find 查找指定字符 ==》找到該字符串的索引位置。如果找不到就返回-1

index1= a.find('wo')

index2= a.find('ow')

print(index1) ==》6

print(index2) ==》-1

# index 方法如果找不到就會(huì)報(bào)錯(cuò) ValueError值錯(cuò)誤

result1= a.index('wo')

result2= a.index('ow')

print(result1,result2) ==》ValueError

# join 組合，連接字符串?dāng)?shù)組。將字符串、元組、列表中的元素以指定的字符(分隔符)連接生成一個(gè)新的字符串?

person_info= ['Tom','男','27','180']

person_info= ','.join(person_info)

print(person_info) ==》Tom,男,27,180

# split 拆分，按某一個(gè)字符分割，且分割n次

person_info1= ('hello,world')

person_info1= person_info1.split(',')

print(person_info1) ==》?['hello', 'world']

# strip 去掉頭和尾指定的字符,中間無法去除

d= '666Helleo 6 python!666'

f= d.strip('6')

print(f) ==》Helleo 6 python!